How many cryptos should Ihave in my portfolio? Are there one recommended diversification ( like having 3 or 4 coins) ?
There is no limit to how many cryptocurrencies you can buy, you are free to buy as much as you want. The only thing you should have in mind is that more coins means more money, so if you are going to buy a lot of coins you really need to have the money to do so.
If you dont have much money then it will be best if you just buy a few coins. And I will recommend Bitcoin, XMR, Ripple, Ethereum, NEO, Litecoin and BCH. I think these are the ones that are trending in the market now, so you choose any of them.