my advice is to learn always the 4 important forms (nouns:gen sg+pl and part sg+pl ///verbs: 1.sg.pres.ind.act.,3.sg.imp.ind.act., past participle active, imperfect passive)!!!!
when i learnt it (in 1988) i haven spoken on a cassette, nowadays google translation tool may read for you, saved with audacity and put onto MP3player, is more modern :-) [huom! sometime "ä" is wrongly pronounced as "a"!]
listened while clearing up, ironing, washing dishes aso. millions of times - I wont forget the sound till the rest of my life, and have always the correct form in mind!
tietää know tietää, tiedän, tiesi, tietänyt, tiedettiin
saari isle,island saari, saaren, saarta, saarien, saaria
otherwise use more ways than just one computer based, write notes and stick them on everything in your flat, use an "overhead pen" and write it on the mirror in the bathroom(to read while brushing teeth), use a traditionally vocabulary booklet, play "Top Trumps" or Happy Families with the 4forms, or just Eng + Finn so Memory or Pelmanism
and build simple sentences with the 4 forms...
(search with google for correct examples!!! dont use learning platforms because there are many mistakes, you may easily copy.. Finnish news paper websides or Finnish wikipedia are pretty "safe" sources to get correct sentences...
the big point is Finnish has an important grammar! you cant stream words like in English-- there everybody would understand(to 60-80% it is even correct) , but in Finnish it would 100%ly incorrect and most ppl couldnt understand it.