For the most part, yes! Croagunk are some of the more laid back fighting-types one can obtain, and thus, they’re also often some of the easiest fighting-types to teach and gain the trust of. Furthermore, many registered leagues start off with a rock-type gym, which can easily be conquered by a croagunk’s Mud-Slap (which it learns naturally) or arsenal of fighting-type moves (which it may learn early by inheriting the technique from a parent).
The only real challenge in caring for a croagunk is really in, well, caring for a croagunk. It’s not exactly challenging to do so, as croagunk have very simple needs, but they do generally need moisture 24/7. As in, their skin must be moist at all times, as they face an increased risk of infection or even heat exhaustion if they’re allowed to dry. Especially if the croagunk in question has the ability Dry Skin.
However, even this is easy to resolve. Simply carry around a spray bottle full of water and lightly spritz your croagunk whenever it looks dry or lethargic (well, more so than usual), and you will be fine.
Best of luck, @ronnoc32122!
The Pokédex According to Bill 