How do I start making custom arts

So I’m pretty new to making proxies but I’ve gotten how to print my favorite art that are actually in magic but I love seeing custom art for cards and I don’t know how to start I have no artistic talent so like actually drawing them is off the table and I want to use absolutely no AI, but how do I make the cards and get them to lay out to size for print there aren’t any good tutorials on YouTube so any help is welcome thanks