Seasoning a grill has no relationship to seasoning the steak or eggplant you're grilling. In the latter case, you season to add flavor to the raw food item. But when you season a cast iron grill, you're not adding flavor. It actually refers to the process of coating the grill grate with oil, then heating it, to render it rustproof and create a virtually nonstick surface. Depending on the type of grill you own, you may only need to season the grill the first time you use it and occasionally after that. And with a Weber brand grill, you may not need to season it at all.
In lieu of fully re-seasoning your grill with each use, there are simple steps you can take to maintain and care for the condition of your grates. After each use, take a moment to run the wire brush quickly over the grates to clear away any immediate drippings. The heat in this case is helpful for removal when in smaller portions and in the moment. In the same step as above, use a pair of kitchen tongs and a paper towel to coat a layer of high heat oil over the cleaned grates before closing the grill top to cool.
The first thing you have to do is get it home safely. (I laughed and laughed when I heard this story). Apparently there is a vacant lot on the corner right next to the local WalMart. The employees at WalMart call this lot the Grill Eater Lot. There are several smashed up grills that ended up dumped in that vacant lot as their owners took the corner too fast and lost the grill out of the back of their pickup trucks (I totally need to drive over there and get a picture). So – a tip for the new grill owner – tie it down before you leave the store :-).
Clean the exterior of the grill. Soapy water is the safest cleaning solution for most gas grills. Just make a cleaning solution with water and a squirt or two of mild dishwashing soap. Wipe the exterior of the grill with the soapy water, use a rag dipped in clean water to remove the soap residue, and then dry the exterior of the grill thoroughly.