How much money do I need to start trading?

If you have to ask, then you don’t have enough. The better question to ask yourself is how many months of normal living expenses can you cover with what you have in your bank account? The answer had better be at least three, ideally six, before you start actively trading.

What should I trade—stocks, forex, crypto, or something else?

You should trade what you know and understand the most. If you have no experience with any asset class, then go with the one you are most intrigued by. Like any other endeavor, if you don’t find the subject matter interesting you will not be good at it.

What is the best trading strategy to use?

OMFG, if there was one strategy that was clearly "best" then everybody would just do that, wouldn't they? There are many strategies that work, at least some of the time. At a minimum, you need to use tactics that make intuitive sense to you. Can you explain it to someone else? You also need to use strategies that are aligned with your risk tolerance.

How do I avoid big losses?

The most effective way to avoid a big loss is to sell when you have a small loss. If you are trading something that is prone to sudden large swings in value, then you will not avoid big losses.

Is trading just gambling?

Yes.

Can I make a living from trading?

This is the king of poorly posed questions about trading. Can you earn a living playing guitar in a band? Yes, it is possible. Can you make good money from Tik Tok videos? Yes, you can. OTOH, if you have asked the first question on this page then you surely do not have enough capital to rely on trading as your only source of income.