I've ran Columbia's Get to the Green race for the past two years and it is a very fun event to do.

When you register for the Get to the Green race, you will have the option to go for the one mile, the 5k, the 10k, and the 15k. No matter which distance you run, you will start at the same starting point, across from Maxcy Gregg Park. The 10k and 15k participants take off before the 5k and the 1 mile people. No matter which one you do, remember that this is one of Columbia's most popular (and populous judging by the amount of runners I saw) and it can get crowded at the beginning of the course. Speaking of the course, it is basically one big loop, except for the 1 mile route. The 5k does one loop, the 10k does two loops, and the 15k does three loops. Because I don't like running laps, I did the 5k and there were plenty of people to run along with. You will see A LOT of green on people while waiting and running, it is a Saint Patrick's Day run after all.

The course itself has a couple of hills but it starts off relatively flat. You will run through residential areas and there are quite a few people who will come out of their homes to cheer you on; the water and aid stations are two water/aid stations along the loop. So no matter what distance you're running, you should have plenty of opportunities for water, though I would suggest carrying some water if you are doing the 10k or the 15k.

The finish line takes you almost to one of the entrances to the Five Point St. Patrick's Day party which also has the parade running through it. There are enough vendors offering food and drinks to keep everyone happy, at least that's what I saw when I left around 2 PM.

Parking can be an issue, because you won't be parking at Five Points due to the the St. Patrick's Day parade and after party happening there. The organizers suggest parking in one of several USC's parking areas west of the starting line, but a lot of people (myself included) parked in the residential area south of the running course and the St. Patrick's Day party because it makes for a quicker exit.

To see what the part of the course and how this race draws out a lot of runners, here's my video highlights from the race:
https://youtu.be/jl25X1vfXFw

I definitely recommend taking part in this race. It's becoming a Columbia tradition and has been around for the past 15 years.