First 5K in 19 days

Hello :)

So I have never run a 5K race, but I have slowly jogged 5K 4 times. Slowly being a very important adjective. I agreed to do a 5K on 8/24 with some friends, and I am wondering if anyone has suggestions for how to work on preparing for it. I do not have a lot of hills near me, but the route for the race has hills. The last quarter mile is on a sandy beach, also. I am just looking to finish the race, not compete as far as speed goes. But I would like to prepare as best as I can.

TIA!