I would definitely recommend you check out www.AmazingRibs.com. It has a lot of great recipes and reviews, and has definitely made me a better griller. You can absolutely cook great food on a cheap grill, it may just require a little more attention while cooking and being very consistent with cleaning. I also second the craigslist weber if you can find one. In bigger cities, ReStores get closeout lots from the big box stores, and you can sometimes nab a deal there.
In terms of extra stuff, the single most important is a probe thermo, I like the ThermoPop. its not as fast as some of their fancier ones, but it gets the job done. You can skip the infrared early on, in my opinion. Second, a seafood basket opens up a lot of doors. I like the clamshell type with the long handle that you can keep outside of the grill, as opposed to the basket with holes. I keep finding these for peanuts in my local Goodwill. These are great for anything delicate, and also bacon wrapped asparagus, etc.
You mention metal working, so keep your eye out for a decent thick chunk of Carbon Steel you can use as a griddle. Make sure its cleaned of any treatment or rust inhibitor. You can find instructions on seasoning it and keeping it clean online. You want to leave some room around the perimeter (~1 inch or so). Cast iron is also great if you can find it cheap/used, I have an old lodge griddle from Goodwill. This is great for breakfast and diner/smash burgers.
Pizza Stones are good also if that interests you. I will say be prepared to spend a few tries on your setup (grill/stone, dough, toppings, loading and unloading process) before you end up with solid pies. You will need a steady high heat, and i recommend a cheap peel from amazon to load/unload if you're going to do this often.
Once you dial in your grill and know its hot and cold spots, you can start using indirect heat for longer cooks (and also the reverse sear that amazing ribs talks about with his steakhouse burgers). This is a good time to consider some of the thermos with probes you leave in the meat, 2 are nice (for ambient and meat temp) but one can get you rolling. I made some amazing pork butts on an ancient char broil that you had to take the whole top on and off because the hinges had rotted off. I used one burner and stuck pecan chips in a foil pouch over the burner, meat on the other side. Had a wedge shaped piece of ceramic from a broke tile that I used to 'adjust' the lid opening until it stayed around 250. Rotated the meat every hour, and it turned out amazing. The tough part of this is you cook by temperature vs. time, which can be tough when you've got the family waiting for dinner and the pork butt has 40 degrees to go - not sure if this is for you solo or you got fam.
Anyhow, best of luck on your grilling journey, hope you have a lot of fun and good meals ahead of you!