Congratulations on the car purchase, and welcome to the forum. You will find solutions here to most any problem you encounter with the car. And there are many members willing to answer questions.

The Homelink in the Limited is old technology. Myself and others have found it does not work with newer garage openers with rolling codes. You certainly could buy a remote receiver compatible with the Homelink that is wired into the garage opener. Homelink is not part of the rearview mirror. It goes in the headliner. You will need to cut a hole for it. I switched to a very small fob remote that works with the newer openers.

BTW, do not feel bad about missing some of the limited goodies. I own two Limiteds and an SE base which is my favorite. Having the extras is nice, but I don't miss them in the base model. Here are a few observations. The Limited cup holder does not work well, get's in the way of shifting, pops up when bumped with your elbow, and will puncture paper cups. Many owners swap it out with the cubby found in the base. The seat heaters often fail in the limited. I find the cloth base seats are more comfortable and give more headroom. The tire pressure monitors are nice to have, but are old tech in the Crossfires. The cars will not automatically learn new sensors. When the sensors fail it's a headache for owners. Tire shops can clone the old ones if they are still working, but they do not have a scanner that can talk to the car computer to pair with the new sensors.