The advantage of applying this year is that most selective schools are test optional, so if his SAT scores don’t shine, it won’t matter so much.
Agree with the comments given his family’s economic situation, working is a great EC.
A lot of this looks daunting right now, but if you break down the process into pieces with timelines, it is achievable.
Start with a list (doesn’t need to be set in stone right away) with 2-3 reaches, 3-5 matches, 2-3 safeties. Within the UC’s you can fill many of the reach and match spots. The safeties can be filled by perhaps some CSU’s or community colleges. As you and your grandson research the schools for your grandson’s list, start noting the components (Common App or school app; tests required/optional, letters of recommendation, financial aid, merit aid) and their deadlines for each application. Run the net price calculator found on the financial aid page to get an idea of affordability. Keep this all organized on a spreadsheet.
Time sensitive items he needs to do now: 1) prepare a “resume” of accomplishments and interests. This will help him fill in a bunch of stuff on the app’s, but more importantly, this is something that he should give his letter of recommendation writers. It is important to get your LoR writers on board sooner rather than later. Some popular teachers may limit the number of letters they do, and being human, they probably spend more time and effort on ones that they do earlier and 2) if he is going for Questbridge, he needs to get started asap. I think this could be a great program for him but that is up to him. Filling in that app will get him well started on the Common App and school apps in terms of information required. I suggest running a master sheet of certain facts in Word (perhaps in the Resume), so that it can be cut and pasted into the other online apps.
As your grandson looks into each app, he should note the prompts and word limits of each essay on his master spreadsheet. This will help him have 1 place to see how many essays of what length he will need to prepare. He can also see if there are common themed essays where he can recycle an essay, usually with some modification, for multiple applications. I had my kids note internal timelines for drafting, revising and finalizing each essay. Spreading essays out and allowing for review time is important IMO.
Financial aid runs on its own timeline. Here, maybe the better division of labor is for you to take control. Getting a handle earlier rather than later is important and you will need the cooperation of the parents. For some schools, aid is first come first served. Also for merit aid, there is often earlier deadlines.
FWIW, your grandson sounds like he is a very independent kid. Maybe letting him go to school far away will be a liberating thing rather than a struggle. You all are the best judge of that, but frankly, once you are an airplane fight away, it doesn’t matter.
Best of luck and don’t be afraid to come back with specific questions on a school or part of the process.