This is very much a trip designed to have you out and about, exploring on foot. In between the more active days, you tend to have easy rest days as you move between destinations.
In the Pyrenees, you have a day with your guide where you are able to set the level of difficulty. There are options for easy, medium and difficult hikes, you simply chat through the options with your guide. If you have a day for the self-guided walk, then takes you into the high mountains, but you're walking a relatively flat trail between the peaks and around lakes, so it's not mountaineering!
In Garrotxa we advise you to do the circular walk from your hotel. It's a decent walk at 11km but importantly it's pretty flat, so it's a fairly easy one.
On the coast, the walks are shorter and tend to lead downhill steadily. There's usually a quiet cove or two to swim in on the way if the sun is shining on you.
All in all, this is a comfortably active trip, but you always have the option of changing plans and using your car to explore instead.