The ace thing is that you have wisdom and are no doubt nose deep in parenting books, so will be a very well informed parent. This will help your child's literacy, fostering a love of reading which is one of the greatest gifts that you can give them.
Keeping fit is key. Toddlers and primary aged kids are high energy, and if you will have just the one child, you will be the default playmate!
I started late - in my early 40s. I'm in my 50s now, and have the same physique as when I was 20 (yay!) due to the vigors of playing tag, chasing, climbing, cycling, sprint training, swimming, playing tennis, playing basketball, hiking, etc. It is involved but you reap the benefits. It is doing wonders for my skin, too.
Home help or being near to extended family can lighten the load when you need a break. This is worth considering, as down time is important whether you are doing this alone or as a couple.
You are going to do fine!