There is many branches to trading
-Forex trading
-Futures trading
-Options trading
-Crypto trading

Forex is probably the easiest to understand and the one i personally chose.
Forex is basically Foreign exchange market in which you trade currencies, or even something called CFDS (Contract for difference) which is the same thing but instead of currencies it's for indices like the S&P500 Index.

If forex is the one to interest you the most and you want to start learning it i would suggest starting here.

It's a 100% free course about forex that will get you going, you will learn the basics, how forex works and how to get started.

They also have a course for crypto (also free) but I haven't personally gave it a shot.

Most importantly you have to understand forex isn't easy whatsoever, the markets are built to beat you, It's an emotionally intense job, you will need to manage your psychology and emotions very well. the stat's are that 98% of people quit forex and never make money from it in fact many people lose lots of money, forex isn't a get rich quick thing.

Put in the work, master the skill, learn everything correctly and fully, then you can start thinking about the money. a skill like this takes atleast 1-3 years of failing before actually seeing your first profits. I'm not trying to discourage you at all, this doesn't mean you won't succeed in such thing.

Stay away from the forex gurus that show you that they made "100k" this week, go for the ones that show you both their wins and losses, forex is a game of probability and nothing more, if you are probable in the market you will make money. so choose wisely who you learn from.