Complete beginner, 2nd hand or new gravel bike?

Hi everyone,

I want to buy my first gravel bike. My intention is mainly to go out in nature during the weekends. So rides of let's say an hour or 4. Maybe here and there during the week for an hour or so. I live in a city, so it would take me 30-40 minutes to get in nature. As so, it'll be a mix of road and gravel that I'll be riding on.

Thing is, I have cycled many years to commute, but it was on a basic cheap bike. I've never rode a gravel bike, or a decent bike for that matter. I think this makes spotting a good bike hard.

My budget is around 1200-1500 euros. I would like to go second hand, but I'm kind of worried of buying the wrong frame size, or even buying a bike that's already damaged, but I wouldn't be able to propely spot the damage. I wouldn't mind to repair things here and there though - would like to learn about replacing / maintance of the bike.

Would you recommend going for a new or second hand bike? If new, I would go to a store and make sure the frame is the right fit and it would have warranty of course.

Thanks!