EURECOM
Hotel
If you are visiting EURECOM, my recommendation is to stay at a hotel in Antibes, the nearest city to EURECOM that is located along the ocean. You can enjoy a pretty old town and beautiful landscapes.
Transportation
From the Nice airport to Antibes (assuming you are staying in Antibes):
There is bus line 250 that goes directly from the Nice airport terminal 2 to the Antibes main station (Pôle d'échanges). You can buy a ticket from the driver (about 11 EUR). https://www.niceairportxpress.com/fr/horaires/3/retour
You can find other ways to go to Antibes here: https://moovitapp.com/nice-3260/poi/Gare%20D'Antibes/Nice%20C%C3%B4te%20d'Azur%20Airport/en?fll=43.659536_7.206153&tll=43.585766_7.119227
From Antibes to EURECOM (and EURECOM to Antibes)
You can take bus line A: https://moovitapp.com/nice-3260/poi/Eurecom/Gare%20D'Antibes/en?tll=43.614258_7.071348&fll=43.585766_7.119227
You can buy a ticket from the driver or a ticket machine.
I recommend you install the moovit app: https://moovitapp.com/nice-3260/poi/en