Warning Lights On, Need Help!

I have a 2006 Mustang w/ 26,000 miles. The car never needed servicing before.

The wrench icon lit up on my dash last month. I saw an online suggestion to disconnect the battery...and I did. It removed that warning light.
Now a month later, the wrench light lit up again yesterday, and today, both the wrench and the engine lights are on, and the car lost alot of pick up

Any ideas what this might indicate?

Thank you.