I had my first girlfriend when I was 23.

I was delayed in a lot of areas to do with social development due to my autism. I'd been trying to get a girlfriend since I was 13 but it took me a decade haha.

Always had girls that were friends from a young age, I really enjoyed their company, they have so much value to give, from my mid teens to late 20's sex with interesting women was a thing, I avoided having a girlfriend until 29yrs old, girls would always ask why I didnt have a girlfriend, I use to tell them I haven't found the right one ;), but in reality I enjoyed my freedom and getting to know as many people as possible on my terms, but once I did "find" her, I married that girl and now have a child together, and I am very happy with how it worked out :)       

I've known her since I was a child. It seems like we've always been together. 

I love her so much. 

I had my first girlfriend at 13 but never kissed a girl until my second girlfriend at 14.
This maybe sound weird but my first kiss was when I was 4 years old, I think we were imitating movies and things we saw on the TV, we used to hide at our kindergarden to kiss and that happened several times, sadly I don't remember her name or anything to contact her, fun times.

At the age of 26. I had a strict upbringing and there was no room to mess up when i was in school. So when i started working at that age, i had my first girlfriend's kiss.

My first girlfriend was at 17, but my first kiss with a girl was at 14. My first "boyfriend" was at 22 (technically we were not boyfriends but we kept a "friends with benefits" relationship for several years).

Same story for me really aged 4 too lol. First kiss before first GF lol.  Honestly no idea why as at the time it was not important. 

Had little flings and short term things from age 14 but I didn't get my first proper girlfriend until I was 15 going on 16. She was the first one I kissed (the others I just held hands with them lol).

Didn't have sex until my 2nd girlfriend which was after I left secondary school though and I was 17 by this point.

What a strange question to ask 

If we are talking real girfriend it was with 17 and kissed on the same day we started dating.
If we are talking about earlier girlfriend I can't be sure the age, but was between 6 and 9, and well we did touch lips, but mostly hold hand.