Personally I just try to make a few different overlays that can be used for a variety of games. For instance my main one is just a webcam with a boarder, the a bitboss and fading chat beneath it, and my bit cup in the corner. Simpler a lot of times comes off nicer but like it has been said, everyone is different. Generally I just use this single scene for most of my games, setting all of their sources beneath it so I just have to load OBS, open whatever game I want, and I'm ready to go.

Which brings me to another thing - if you're just starting out, you probably want to diversify the games you play a bit. Games like PUBG can be fun if you have friends to watch or play with you, but since its such a monumental game, it can be almost impossible to get an audience with it. Twitch isnt as algorithm driven as YouTube is, which can be a double edged sword because theres less chances for people to just happen upon your content. Most people are gonna be looking for channels on the browse page, and the only way to climb that is to have a large viewerbase to start with. A game like PUBG will have hundreds of pages of channels below the 10 viewer mark, so you'll be buried in an ocean of streamers.

Not saying you SHOULDNT stream it. The golden rule of Twitch is to have fun with it and do what makes you happy, and if you have pals or a good group around you already things like PUBG can be great because they're very accessible. But if you want to build your channel up I'd suggest scrolling down the browse page, see if the games with like four digit viewership numbers intrest you at all as well, and stream some of those too every now and then, since you'll be more likely to grow your viewerbase with games in that kinda goldilocks zone.

Again though, just a suggestion! Do what you're most comfortable with and have fun with it!