Catrin, if you don't have a floor pump, you should definitely get that. I generally check my tire pressure every second or third ride before I head out, and use my floor pump to top off the tires as needed. My floor pump has a gauge on it, which I find very handy.

I've had two flats in six? Seven? years. I've used more CO2 on other people's bikes than I have my own.

You should also look into getting lights of some kind. I used to have no lights and therefore didn't ride after dark; that said, there were times in previous years when I miscalculated time/distance/sunset and was riding in conditions in which some kind of light would have been A Really Good Idea.

If you are planning on not riding after dark, I suggest getting something cheap and little Just In Case. I got these and dropped them in my handlebar bag. I have lights on my bike now, but if one goes, or I'm riding with someone who doesn't have lights, or I want additional lights on me, I have these as spares. I wish I had had them when my son and I ran out of sunlight on one wooded trail some years ago; we really could have used them. It was dark out there!!!!