in the stock market can you take out your investment when you want to?

Answer 1

I would not say “take out”

It’s more like sell you share to someone else. For the most part there is always someone who is willing to buy at the market price. But let’s say hypothetically if no one want to buy your share(s) then you will be suck with it.

Answer 2

Essentially yes. You can sell stocks at any time during market hours (930am-4pm Mon-Fri and excluding holidays eastern standard time for the NYSE.) It is often possible to sell stocks outside of those hours (this is called an extended hours trading) though you're likely to get a worse price for them.