Planning my future!

Me and my SO have been going out for a year and a half and we love each ither soo much, were both 21 and he is currently in uni,we have talked abiut moving in together but are going to wait till he qualifys and has an income, but just wondering what is a good age to get engaged and married and have kids! I really want kids and dont want to leave it too late incase of any complicstions! Want to no what you think