What app should I use to invest in crypto?

I already have a round $600 or so in BTC on cash app but was wondering if there are better apps I could use. Ideally I'd like one that either gives tips for when to buy/sell and how much, or an app that allows for users to invest in more than one cryptocurrency (unlike Cash App). Does an app like that even exist?

Additionally, if there's any advice you could give me on how to best start out strategy-wise then it'd be much appreciated. My goal is to make a profit in the long term but I'm not exactly sure how I'd go about doing that.