Some people do just fine with a lightweight popup camper on a half ton truck, without a bathroom and a shower. Others need an F450 and three slideouts and a dry bath. There is no right or wrong, it all comes down to your personal needs and wants. You need to find out what is right *for you*.
Check out the buyers guide over at truckcampermagazine for an overview of current campers and their respective weights. Note that the stated weights often are not reliable.
If you have neither truck nor camper, find a suitable camper and get a matching truck.
As far as payload for campers goes, it is never a bad idea to have "too much truck". You will find that numbers that never meant anything to you as a car driver suddenly become meaningful, mostly GVWR (Gross Vehicle Weight Rating) and RAWR (Rear Axle Weight Rating). See also: Door Sticker. Tow ratings as well if you want to tow, but that is another topic that you need to research if/when it comes up.
A long camper with a lot of overhang on a short bed truck can badly overload the rear axle without overloading the vehicle. It will help if you understand what the Center of Gravity (CoG) on the camper means and where to find it.
It is of course possible to overload the truck, even though it is often illegal to do so. Many people do it without problems. Some things can be done safely, others not so much. If you don't know exactly what you are doing, just don't do it.
If the camper weight and truck capacity match well, the whole rig should handle just fine without modifications to the truck. The camper and truck in my signature handle very well together. But the truck is a fairly lightweight 2WD regular cab work truck.
2014 Ford F350 XLT 6.2 SCLB + 2017 Northstar Arrow