Look for airdrops. They will get you some free coins and you can use them to start trading.
There are a lot of airdrops around, just google for 'airdrop cryptocurrency' and you'll have some points to start with.
Next to that, there are a bunch of guides explaining bitcoin and cryptocurrency trading. Surf around the forum ;-)
Yeah, airdrops and bounties are good option to start but be careful and cautious as there are lot of scams too. Search on this forum how can you find legit ones and take part in them. They'll give you a good start for the trading and investing.