Welcome aboard! You're probably getting close to the limit there pulling a 21 footer with a Cherokee. But the older ones were lighter than the new for a given length so you may be OK. A V8 Grand Cherokee or Hemi Durango would be better, but you might squeak by if you take it easy.
Is your Jeep an automatic or a manual? If an auto, probably shouldn't tow in overdrive (if it's got one).
For safety, the biggest thing to remember is that having enough chassis is more important than having enough power. In other words, you don't want the trailer to "drive the truck." Your owners manual should tell you what weight the jeep is capable of pulling. You can probably find a published weight of your trailer on these forums by using the "search" feature and looking for weights. But, a better way is to actually take it to a scale. General recommendation is to try to keep the trailer to 80% or less of your tow vehicle's capacity. So if your Jeep was rated to tow 6000lbs, you'd want to try to keep what you tow down to 80% of 6000lbs, or 4800lbs.
Best of luck!