here is a list of great things to do in tsfas both on shabbos and during week.
there is a friday night tour of the old city which is great.
see all the old shuls: beis yosefs, abohav, arizal.
arizals mikvah and the arizals, beis yosefs and rav shloima alkabatzes kevarim.
walk around old city and check out the different art galleries.
the tzfas winery. amazing and different than other ones you may have visited. one frum guy makes the wine with his sons, stores the barrels in his basement, and spends the rest of his time learning. interesting, tastes good.
obviously miron is nearby if you have time before or after shabbos and there is an amazing hike that takes about 2 hours from tzfat to miron.
foodwise: rechov yerushalayim is the main street. there is an amazing mehadrin falafel. smal place, guy makes everything only once you order.
in reference to previous comments: carlebach shul is packed on popular weeks like chanuka but otherwise not bad. nice for friday night and before mariv on motzei there is a kumzitz.
I dont know what your budget is but the nicest hotel in the old city is the rimonim. you can preorder mehadrin meals for extra money and the mashgiach personally arranges everything
ENJOY!