What parts to replace on a high mileage car?

So I'm thinking of getting between a Ford Bronco or a 4Runner to do light off roading and camping and having it for years to come. Not looking to spend more then $10k but at that price most of them have high mileage. So if I find one in good condition, what should be some things I replace and do for services?

Not many parts but you can of course see what's wrong with it if you go to the dealer

Be sure to inspect and test the parts that could leave you stranded (which are most, really)
Engine, esp. Belts, water pump, hoses, radiator, ignition
Transmission
Fuel system, esp. Pump, tubes, tank, indicator (don't want to be caught out of gas when you thought you had more)
Tires, wheels, bearings, bushings, shocks, even springs
Just imagine being miles from anywhere and a breakdown leaves you stranded, perhaps alone. You might invest in a satellite phone to insure you can communicate.

It depends on how those high miles were clicked off on the odometer.

If the vehicle was used for any kind of off-road driving, you'll need to replace all the parts. I don't care what they show you in the commercials, no personal-use vehicle was designed for off-roading. The two most effective ways to damage a vehicle are to either go head-on with a train or drive it off a cliff. The third most effective is to do anything you've seen a vehicle do in those 4X4 commercials. I've done it, and it's really expensive.

If the vehicle was used anywhere in the snow belt, you'll want to check for serious rust damage to the body and undercarriage. If it was used for city commuting, pay attention to the brakes and suspension.

See how this works? It's not how many miles the vehicle has been driven, it's how they were driven.

Replace what needs to be replaced. If it's still good, leave it alone…

I wouldn't just start replacing parts. Get your mechanic to do a pre purchase inspection. Look at the parts (if any) that are flagged as having a problem or in questionable shape. Part of the decision is how critical is the truck to you, if you can't afford to have any downtime, that's going to drive you to replace some parts earlier than if you can handle a breakdown or a problem.

Replace everything attached to the gas cap.

I take it to a pro shop for an inspection. Preferably b4 purchase. Likely they'll find all the major issues. Might not see all the little issues. For those, I suggest getting an owners manual and go through the maintenance schedule. Starting from the beginning. B4 you do that, replace all fluids and any consumable ignition components. Doing that sets a good base line for trouble shooting/periodic inspections. Otherwise false trouble shooting conclusions will happen.
we could list all to look at here. Might miss a few. There's lots to look at when used. But the app service manual will cover all.

I don't know much about those rolling off the assembly line as we speak, but wise choice on bronco or runner! Those have a stellar rep/pedigree. Decades of reliable service from those.
I believe you can find a bronco w SAS (solid axle). Those will tackle anything. The runner has an independent front suspension. Not as capable, but for light off roading/camping, should serve you well. For the yota brand, SAS can be found on the cruiser model. If you so choose.
to be a bit more comfortable driving when taking long trips to your destination, might not want SAS. Either, given your parameters, will do the job.

Injectors 1st, egr cleaning, coil pack, distributor cap rotor… Brakes, bearings…

Depends on what condition it's in and what it needs. I always pull the wheels and check the brakes first thing.

Belts and hoses if you plan to go miles away from any where that way you have a spare set which hopefully you won't need to use. Along with a general inspection replace what's worn, plug leads if it has spark plugs if it needs them?