If I were you I wouldn’t use GCSE or A-level resources unless you really like them, they generally teach you things that people don’t really say and are quite dull. I got to about a B2 (it’s hard to tell) in roughly a year without any sort of textbook apart from the first 20 lessons of Assimil (after this I got bored but it is a good resource for people with longer attention spans). These are some of the things I did you might like to try them and see if they work for you too.
When I started out learning French I watched youtube videos (made by native speakers for native speakers with French subtitles whenever possible). Because they are usually less than 10/15 minutes long, it isn’t as tiring as watching movies or TV shows, so you can watch the same video multiple times but not all on the same day! If you go down this route you will hardly understand a thing but once you start to understand just 10 consecutive seconds you will feel like a genius. If that was getting too hard I also watched kids cartoons like L’âne TroTro on a loop. I would look up the words that I could pick out in a dictionary but I wouldn’t stress out too much. There is a free site called rhinospike where people transcribe youtube videos which is helpful if there are no subtitles. Don’t bother with English subtitles, unless it is just on the first run through to get an idea of what is going on. The main goal is to train your brain to pick out individual words and get an understanding of how people really speak and behave (body language and stuff), so that when you have face to face conversations you won’t be as lost.
If you want to get to B2 you need to have a knowledge of a wide range of topics (not the ones on the test) so take an interest in as much stuff as possible.
There is a directory of French youtubers at youtubeur.net but if youtube isn’t your thing try Le Petit Journal on canalplus.fr or on their app. It’s a news show for people in and around their 20s I guess (a sort of more grown up Newsround which is actually entertaining). You can google the topics they are talking about/people they are interviewing to give yourself some kind of idea of what’s going on. There aren’t any subtitles but sometimes they put words on the screen and it kind of helps to understand what’s going on. It’s light hearted entertainment rather than serious news and it’s pretty funny most of the time. You can also watch a lot of other shows there for free. Click on the Emissions tab.
If you have Netflix and a VPN you can watch Netflix France (this is not against the law but it is against the Netflix terms of service as of April this year). There are a lot of French subtitled movies and shows, but if the film/show is dubbed the subtitles usually don’t match the dialogue so be careful about that. I watched kids shows like Wakfu, and French TV shows rather than dubbed stuff, but lots of people like to watch the French version of English language stuff that they are already familiar with.
I changed all my electronic devices to French, which meant most of my ipad apps switched to French (not fun at first) and I spent any other time I had listening to French music.
I would do all this alongside reading everyday, but I would never read without audio until at least 6 months in (except for Asterix, comic books are great for learning languages). Lingq is the best resource for reading and listening at the same time or shadowing audio.
I tried other sites like Memrise and Duolingo but that kind of thing didn’t work for me, although I did complete the Duolingo course. They both lack context and Duolingo has a robot voice, although there are whole sentences there (don’t try to learn individual words it’s not as effective). Sites like these are good for refreshing words which you probably learnt at school and have forgotten, but I also think they have a tendency to sap your time if you are not careful and I wish I’d noticed that sooner.
I also wrote and tried to get corrections from native speakers. You can use bonpatron.com, which is a free spelling and grammar checker, before you ask someone to correct things for you, to cut down on your mistakes. When it finds a fault, it usually explains what you have done wrong but it’s like any spelling and grammar checker ie not perfect.
There are sites online and on youtube with dictées for primary school kids, these are good ways to learn spelling and grammar rules without too much effort, I only did a maximum of one or two a month if I felt inclined to do so, there is no point doing things like that if they feel like a chore. They are all for native speakers so I had to be at a level where I could understand the explanations. That is how far into the process I was when I started to care about studying grammar. You could also use Lingq for this, transcribe the audio and check with the text.
If you don’t like dictées there is a site called lyricstraining which plays a song and asks you to fill in the gaps in the lyrics which you can start doing from day one. It’s free and it is a good way to learn vocabulary as well as spelling. You may pick up on grammar rules by doing this but probably not. None of the lyrics are translated so you will have to look up words. The online french/english dictionaries I prefer are wordreference and reverso (Collins). Wordreference forums are good to use and reverso has a context search and a translator which are both handy tools (if you use google translate and it doens’t make sense, cross reference it with the reverso translator, but translators are not something to rely on a lot).
One thing I would have done differently would have been to talk to native speakers, or anyone with a good level of French, earlier. If you aren’t ready to talk out loud apps like hello talk or internet chat rooms are a good compromise. It gives you a lot of confidence and motivation to know that you are able to communicate with other people.
All that is really long so kudos if you actually read it. Not everything I did will work for you and maybe you have already done/or are doing those things. Just don’t try to force yourself to do anything and if something doesn’t work move on to the next method before you lose motivation. Don’t rule an approach out forever though, sometimes I try things again two months later and I actually like them the second time round.