I was also stuck at like 50wpm and I knew it was because of using the wrong fingers for the wrong keys. Someone recommended typing.com's complete beginner lesso

I was also stuck at like 50wpm and I knew it was because of using the wrong fingers for the wrong keys. Someone recommended typing.com's complete beginner lesson where they literally just walk you through which fingers to use with which keys and after completing that and 2 days of practise my speed jumped by 10wpm. Highly recommend.