One more thing on SJC: depending on what airline you use, you will end up at the “old” (Terminal C) or “new” (Terminal A) terminals. Terminal C seems to have been built when the pharoahs were young (and don’t ask me why the hell they call it Terminal C, if its the old terminal); they actually pull up a flight of stairs to the jets and you exit the aircraft down them and hike across the tarmac to your gate. Which isn’t a bad thing in nice weather, and it often is nice weather. But if you’re rolling a big carry-on you have a bad back, I’d check it in instead.
Southwest, Hawaiian, and American (there may be others, not sure) use Terminal A. All others use Terminal C.