You'll definity know it if you eat too much, and it will likely feel uncomfortable for a while. I had a couple of intense experiences, one ended with vomiting, the other I had to just walk it off for about 45 minutes before I felt somewhat normal. It can be quite uncomfortable and induce a little panic because it doesn't feel like it's going to go away, but it does. It might feel like you should drink to get things to move, but that can make things worse sometimes. Little by little and stopping before you physically feel full are keys to avoiding issues.
Eat very slowly. Don't eat until you "feel" full, at that point, it's probably too much. I don't remember if you got VSG or bypass, but either visualize what the actual size of your stomach/pouch is and don't eat any more than that, and/or be sure to measure to ensure you don't go overboard. Eating very slowly will help your brain recognize you are satiated and help you recognize when you should be done.
There is a learning curve. You'll probably make a mistake here or there, but you'll also learn from them pretty quickly.
Take everything slow, even if it feels like you can do more....always wait before having more.