Oil Pressure/check Engine Light

It's probably a good idea to replace the dipstick with the correct part if the one on the car has been messed with. There are a lot of places online where you can order the OEM part. You might also want to replace the dipstick tube as well, just in case a previous owner messed with that too. Is it the stock oil pan or an aftermarket pan?

Once you have the oil level resolved and can confirm the proper fill, I would strongly suggest running a compression and leak-down test. Those results coupled with oil pressure will give you a good picture of engine's health. If any one of those three don't read correctly, then you'll probably have to address a hardware issue or do a complete rebuild.

There is an oil level sensor on the side of the stock pan which could be bad or have a wiring issue, which would trigger the low oil light. If it's the check engine/service engine light, then you'll need to pull codes.

Good luck, I hope it's not too serious.