u/Glittering_Garlic_24

I am 22 and started investing 3 months ago. Below are my current holdings:

30 NVDA $190

25 AMZN $198

12 GOOG $342

10 MSFT $408

I watch videos and read reports to make a decision on when to buy what, and so far I think I have played it pretty safe but I never really know if I am doing it right. I also don't know when to realise my P&L. I do want to max out on profits which is why I don't have QQQ or VOO. Is it advisable that I sell off some holdings to buy index funds as such? If so, which ones and in what scale? Thank you in advance.