I haven't heard of any special tours because of the eclipse, but it is still early so they might not be set up yet.
Hillsboro is close to the I-35 split, where it branches into I-35E and I-35W from the south as you approach Dallas and Fort Worth. I've stopped there a few times while driving; there's a Starbucks with easy access to I-35 north, and Hampton Inn. There are several Kolache shops in the area (central Texas is known for them). There is also an outlet mall, but I don't remember what shops are there.
Otherwise, I can't imagine spending any significant amount of time there.
There will be decent views of the eclipse from Waco, which does have Baylor University, the
Wooly Mammoth National Monument, and if you're into Chip and Joanna (of HGTV fame) the
Magnolia Market. Our local PBS station has a program called, "Texas Daytripper," which dedicated a
full episode to Waco.
I would highly advise getting a rental car for any exploring in this area. You might be able to survive with a bus / coach, or even Amtrak, and using rideshare, but your own vehicle would give you much more flexibility.