The 1998 Jeep Grand Cherokee TSi is a relatively difficult vehicle to maintain, and is only recommended to those capable of vehicle maintenance. You will have to use a few tools to completely remove the tail light housing for access to the bulbs. Other models will make this housing easier to remove. Changing the center brake light will be tough to do with reliability, as you will need to use many tools, and work in a cramped space, for access to the bulbs. You will have to completely remove the bulb housings for access to the front turn signal bulb. The tools necessary may not be readily available for a repair.
Some things are less problematic on the 1998 Jeep Grand Cherokee TSi. Changing the engine air filter is easy to do, as you only have to disengage a few fasteners for access to the filter. These fasteners are easy to disengage. Changing the headlight is easy to do, as you only have to reach behind the housing for access to the assembly. The engine coolant reservoir is easily visible in the engine bay. This will allow you to check and replenish the fluid level on a regular basis.
Hans Angermeier has produced over 100,000 videos showing drivers how to fix things on their cars. He has broad expertise on basic repair procedures covering the majority of cars on the road.