For all those who are taking multiple courses - How confusing does it get?
It can get pretty confusing, but I love it! Writing new vocabulary in each language helps a bit not to get them mixed up. If the languages are very different, like Swahili and Greek or something, it's easier to keep them straight than, say, Russian and Ukrainian. If you want to try another language, go for it!
I'm currently studying German, Norwegian, French, and Russian daily on Doulingo. All of them are quite different from one another, so I rarely if ever confuse them. It really depends on which languages you are learning simultaneously. Are they similar?, or are they vastly different?
Getting things mixed up shouldn't be much of a problem if the you're learning two languages that come from two entirely different language families ( like French and Russian ), but you might encounter a few troubles if you decide to study two languages that are closely related ( like Norwegian and Danish ).