Companies like Meta do you sell and reinvest or wait for the best?

I started investing recently and bought some individual stocks like Meta at 234$ which seemed to be at a low price at the time and some other stocks.

I know that you only loose when you sell but my question is having your money stuck in companies not doing well is a waste too.

Is it worth it to take a 5 to 10% lost and invest in a pretty cheap market or wait for this comanies to recover? If I wait then I'll invest at a much higher price probably.

I know you're suposed to buy low and sell high but I didn't for instance bought Tesla at 770$ because of this companies and I would have recovered my lost already.