Honestly, the answer depends on the bench you buy, but most standard park benches are easier to disassemble than they look. If you choose a model with a bolt-together metal frame and separate wood or metal slats, you can usually break it down with basic tools in under an hour.
The key is to avoid fully welded frames or benches that have been permanently cemented into the ground. Welded joints make it almost impossible to take the bench apart without cutting metal, and ground-mounted benches often require digging or grinding off anchors before they can be moved. For a typical freestanding bench, however, the seat slats are usually held to the frame with hex bolts or carriage bolts, and the backrest attaches in the same way. I have moved several of these by removing the slats first, then unbolting the side legs from the crossbars. That also makes the pieces light enough to carry without help.
Before buying, look for terms like modular, flat-pack, or bolt-together construction. Check the product photos for visible bolt heads instead of smooth welded seams. If possible, download the assembly manual from the manufacturer’s website and see how many parts are involved. A bench that ships unassembled is almost always easier to disassemble later because you simply reverse the steps.
When you do take it apart, keep a small bag or jar for the hardware, and label the parts with masking tape if you will store them for a while. A socket wrench, an Allen key set, and some penetrating oil for rusty bolts will save you a lot of frustration. If the bench is anchored, unbolt it from the concrete pad first rather than pulling on the legs.
So, yes—if you want a park bench you can move later, pick a bolt-together metal or wood model, avoid welded and permanently installed units, and set aside about thirty to sixty minutes for disassembly. That gives you a sturdy outdoor seat now and a realistic moving plan later.