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There's a Q&A thread but if you have an android, someone made an app called SIF Train. You'll need to look at the wiki and load the beatmaps and music yourself, IIRC. There should be a Japanese app too but I'm not sure about the name of it off the top of my head and what it does is take videos from YouTube and let you tap, so it's less intuitive, I think?
Another option would be to have a separate account all together to use as a practice account, that way you could mess up without worrying. If you look up songs on YouTube there should be a couple that have smaller screens on them that help with timing/the beat but I personally just look at the actual videos and tap along. You'll git good, promise.
turn down the text size and make sure nothing distracts you. on youtube, there is a channel that has guides of nearly every song on EN, and a lot of the JP songs. listen to those before you play your song and it will help a lot. i haven't tried it out yet, but there is an app on the google play store, called SIF Train and you can practice the songs on there without having to worry about LP. also, perfect locks. you can make a team of perfect lock cards and use it.
it'll take a while to FC your first 11 star expert, (i took 5 months, serious) but you will do it!