I'm no expert either, but I can briefly explain how much I understand as far as what you're inquiring about. Anyone feel free to correct me.
Level kits would typically be a couple of spacer blocks that would add an inch or two to the front and/or back. It just changes the stance of your truck so that the front end and the back end of your truck are at the same height. I think our trucks have more height in the back so a level kit added to the front would make the front and back of the truck at the same height. A level can also be achieved through suspension upgrades.
I would consider a lift kit as everything you need to get your truck to lift a determined amount. This kit may be various combinations of spacer blocks, front and/or back suspensions, leaf springs, etc. Depending on how much off road you may be taking your truck, the recommended way to lift your truck is going the suspension route.
As I'm typing this, it has kind of opened up a rabbit hole, we can go on and on. haha. Sooo... I think the better start to help give you advice is what do you plan on doing with the truck? Mild off roading, overlanding, rock crawling? Knowing this will help some of the more experienced guys on here help you towards a certain direction.