I always try to settle near high production and high food if I can, because that is vastly more influential for a good game than some long term benefits such as ideal settling for a cluster of high adjacency industrial zones/harbours (which lots of people want to do).
Ideally in combination, because it sucks having a population 5 city with no production, as much as it sucks to be starved for growth at population 2.
That being said, I try to get a combination of both yields (2f/2p or better as an immediate tile that I can work), though I value production a bit more than food if I have to choose.
This is because I can salvage a game by getting out my first settler at population 2 that much faster, but I cannot really salvage a city that only has high food but nothing else going for it.
I also value any tiles that have faith or culture on them, and will easily spend a few turns walking my settler close to a tile that has one of those yields (as long as it doesnt really compromise on food/production priority).
Having free faith allows you to get a pantheon of your choice much faster than waiting for faith through god king, and its also "free production" in that it allows you to run urban planning (one of the best cards in the game early on) over god king (which you only pick for the pantheon anyway).
Some exceptions apply, as you should of course pretty much never work a pearl tile unless it is absolutely critical for your starting location (plenty of desert for instance, for desert folklore).
Having free culture equally allows you to get to god king faster in case there isnt faith available, and has good long term value as well which lets you delay a monument.
I should disclaim that this is mostly important on Deity level play, because you can still get a good pantheon early on on King level, while it is nigh impossible to consistently get any good picks on Deity if you do not have a faith tile to work.
I also almost without deviation produce a settler as my second build item, usually after a warrior or slinger, because having that second city up is absolutely crucial for me for snowballing fast.
Edit: While potatomcwhiskey has some good videos on settling spots, he does make the awful mistake of valuing long term benefits too much.
Case in point, one of his videos has him settle suboptimally because he wants a high adjacency harbour later on in the game.
A harbour arrives relatively late as a build option in this game (around the early mid game), and initially just tends to give you an extra 1-3 gold if you get good adjacency on it over placing it suboptimally.
1-3 gold in the midgame is an absolute joke to prioritize over a good ancient era location, and while you can get extra production on it even later in the game, that extra late game harbour production will never be worth delaying your ancient era snowball for.