Welcome to the A-T-L!
Hi Merianny10.
I live in Cobb county. I know there are a few of us here but most Dominicans probably live in Gwinnett county. They have restaurants, a shipping company, salons and bakeries there. Check out Jose Jimenez's Dominicanos en Atlanta Facebook page for updates on events. He also has a spanish music segment on Saturday's from 7-10pm on 89.3 WRFG.
There are many night clubs and dance halls that cater to latinos. Google PasoFino dance in Atlanta. They are a dance school but they have weekly and monthly bachata & salsa meets where you can just watch people dance and/or mingle with the crowd.
I also see quite a few hair salons popping up all around town. Your best bet is to visit these places and introduce yourself. You will eventually make some Dominican friends.