my gas cap light and my check engine light came on

Hello, First step is to inspect the gas cap sealing ring. The seal may be worn out, and this would allow a leak to occur. If the sealing ring is not cracking or deteriorated (looks new), try cleaning it with wd40 or penetrating oil, then cleaning the filler neck with a rag. If that does not work, replace the cap before you seek diagnostic help. Better to spend a few dollars on the likely failure before paying for diagnostics.

A leak anywhere within the EVAP system will illuminate that light .. Fuel cap is just a possibility and the more common failure .. After playing around with the fuel cap - you'll likely need a scan test and possibly a smoke vapor test to locate the leak.