Tips for buying a used car under $6,000

I'm in need of a car. I can only spend about 6,000 dollars and I know near nothing about cars (as in, "I'm still trying to figure out what a cylinder is" nothing). Different forums say that spending 6 grand on a car with around 150,000 miles is stupid. But all the $6,000 and under cars at every reputable dealership where I live all have 150,000+ miles on them. There's actually very few with only 150k miles on them, most are in the 200k range. I know absolutely nothing about cars, nor do I know anyone that does so I really can't do a private sale. It will have to be a reputable dealership (not "Auto4Less" or something like that). What should I do? I'm in the market for really anything that works. Probably Honda or Toyota. Anything that will last a long time and is cheap to maintain.

Yes

A decade old, give or take, Honda, Toyota, or Mazda would generally be your best reliable choice.

Only consider vehicles for purchase that the seller can show you full proof the vehicle has be fully and properly serviced and maintained.

Remember, sellers will always ask more than they are willing to take. You can find the current market value of any car you are considering here.

https://www.edmunds.com/appraisal/

Buyer beware.

Avoid any car with over 170,000 miles.
Avoid any car that has a bad title.
Avoid any car that has been wrecked.
Avoid any car that doesn't run or drive like it should.

If you know nothing about cars, pay a mechanic to inspect the car for you.