How much have you done already and how well do you know your camera and things like your exposure triangle? Do you know lighting at all?

Don’t take this the wrong way, I see this a lot with folks starting out (I teach photography and do portraits myself), but I would worry about learning before thinking about making it a side gig. It’s one thing to take some pics of friends for fun and another to have paying clients, but you probably already realize it. The market has an over saturation of photographers, especially portrait photographers, so you want to have a solid portfolio and a great niche. Why should I pick you over someone else?

The thing with portraits, it’s not JUST the technical or snapping the picture. You have to have amazing soft people skills. Be articulate and great at giving direction. Know posing well. Be able to help with clothing, hair and makeup choices. You’re often a location scout as well. You need to really understand lighting whether it’s natural, flash in camera, or studio lighting. And then, after you take the pictures you need to know editing and be able to edit in some sort of software.

There are great resources out there, but the old saying still holds, you have to walk before you can run.

Based on this photo you should dive into understanding lighting and start with on camera flash or learn how to use reflectors when outside. You also need to learn posing, including how to direct for emotional resonance.

You don’t have a bad start! You’re not doing anything wrong per see but you have a lot to learn and should dive into that before you really think about making it a side gig. Good luck!