How can I make a lot of friends online ?

start playing online gaming. either on PC or console. try to stick with the same players and just talk about the game. then you can ask to meet up online for future gaming. if you just talk about the game and not troll while gaming or trash talk, you'd get a better chance of making connections.

if you're on Xbox One, there are clubs you can join to help meet new players based on various preferences.