What did you learn from being in your first relationship?

I've been dating someone for about 6 months and we have both talked about how we are at the point where we need to decide if this is a serious partnership or just fun. I am so happy when Im with him, hes smart, thoughtful, driven and we have incredible chemistry together. I love him a lot. My only issue with him is I wish I was more of a priority time wise for him. But i also know he just started an intense new job and is looking for an apartment so im trying to be chill.

He's said the one thing thats making him feel unease about me is my lack of relationship experience and that I sometimes exhibit only child syndrome. These combine to make me a little selfish and needy sometimes (i agree and ive been working to fix this). I cant change my lack of relationship experience. But hes also said he knows I have a pure and kind heart. So it is what it is for now.

But im curious. What are somethings you learned from being in your first relationship or what advice would you give someone who hasnt had one but might have one soon ?

It feels so silly thinking like this at 32, but I know straight people get like a 15 year headstart on this stuff. I really care about this guy and want things to work out.