in graffiti terms: getting your name (tag) up

When someone goes to the gym and spends 90% of the time on their phones scrolling through social media

to graffiti tag your name in a public place

It is to leave your name or tag up somewhere. In today's graffiti world it is a generalized term signifying earning a reputation by placing your moniker somewhere whither seen or not. Traditionally "to get up" meant to place one's graffiti name in a high and visible location like a Billboard, Rooftop or High Rise i.e. literally "Getting Up" somewhere high and visible in a sometimes difficult spot for notable and street fame.

Aquiring an erection.

This term is used in tagger speech. Its is defined as: repping you name, to show that ur the bast tagger out here, and no one can stop you from doin what you do best.