Until this afternoon (Wednesday, 10.07.2019) you can book the direct shuttle bus from Palacavicchi to the Tre Fontane Stadium via the EuroGames website. The timetable of the dance competitions on Thursday is scheduled that you will be able to take that bus at 5pm.
To access the opening you need your EuroGames badge.
Further information on the opening and closing s. EuroGames website: www.romaeurogames2019.org/ceremonies.