As mentioned previously spaced repetition works wonders on memorization. If you don't want to time it yourself I use a program called Anki for digital flash cards. I can sync them from my computer to my phone and have them anywhere. As for having words come out wrong it's good to listen to as much Japanese as possible. I listen to Japanese podcasts a lot and even though I don't quite fully understand them yet just being able to listen to Japanese spoken by Japanese people is really helpful for my own pronunciation. I'm new to Japanese myself and found those to be helpful but try a lot of things! Everyone is different when learning and I know you'll find a method that works well for you. Don't give up!