I'm using a great free graphics editing software called paint.net to make these. You can download it ready-to-go straight from the site. It was the first graphics software I tried when I was getting started 100yrs ago and, while I've noodled around with more advanced (read: expensive) ones, I still love it the best. It's very easy to learn. If you decide to try it out and run into things that make you go Hmmm, I can probably walk you through them.
Note - I don't get anything from the company for promoting the product. But I do get a lot out of being of service to would-be artists... like, personally. So if what you see me doing here inspires to you try something new, it's a win-win type of deal.
▶️ 3Speak
I love em, thanks!