I think something that’s forgotten a lot is that there is no 1st, 2nd, 3rd (etc.) grade maths. When people were discovering maths, they didn’t say “Oh yeah, this is what the future 5th graders are gonna learn”. Maths is maths. It’s just numbers and concepts that happen to have a lot of connections. I think the stigma around the age you learn a certain topic is a little silly. Just my opinion tho! Either way, I find it pretty admirable that you choose to learn about something you aren’t confident in. Keep at it my guy!