great platform to start trading its localbitcoin.....then afer you can go to paxful but you have to read all books from bitcoin.org, and dev boad on this forum
as a beginner you should first know their forums for you to be able to do trading so i guess the perfect that you will do is to gain knowledge and thoughts on how to trade, learn on to those who are doing trading or make search in youtube on how to do trading that was the best way to do when you want to trade.