Influencer is usually the term people slap on content creators they don't like. Content creator is better - and pretty self-explanatory.
The way to become one is simple: figure out the content you want to make, then find an audience for it. Once that audience gets big enough, you can monetize in a few ways. On something like YouTube, you just turn on ads. A step up is landing sponsors - still basically ads, but they pay better and you get more control. The third option is direct follower support, which is possible in theory but almost never turns into real money.
I'd say just pick a niche and start building an audience. If there's actual demand for what you're making, the money will come eventually. Worrying about monetization before you even have viewers is pretty pointless.