My first was only about a month old the first time we went camping. We are fortunate enough to have a pop up camper with plenty of room, so it worked out just fine. Now my oldest is 6 and my youngest is 3 1/2 and we're expecting #3. We've had tons of fun, done canoe trips, etc. If you are active enough, in combination with that fresh air, by nighttime they are so worn out that you'll be surprised if you have to lay down for even 5 minutes with them!
For the camper, we brought the bed rail from her bedroom and used that on one side of the mattress. On the other side, we set baggage so she wouldn't shimmy out the end of the bunk in the middle of the night!!
One thing we have found helpful that took us a bit of adjusting is to check out the campground amenities. Not so much a problem when they are younger than 2, but, now we need to have a play structure, water feature, trails, etc. Pre-child years we loved camping at our fine MN state parks with nice wooded, secluded sites. Now that our kids are more active, the state park amenities can be challenging.
Good luck and Enjoy!!