It depends on what your goals are, mine is 50/50. 50% of my extra I save and the other 50% invest in BTC and Stocks
Of course not, you can save and invest at the same time. But on the other hand you could also keep working and saving up that way. I'd rather do 80/20 so if i'll lose, it won't be that much. It might take me longer to reach my goal but it's better to be safe than sorry later on.
Saving some, and investing some to spread risk.
Spreading risk is mandatory when you deal with money. It's a smart man's game!