I'm not that familiar with the Piedmont of South Carolina but I'd guess the best time to start beet seeds out of doors is to sow them maybe early March for a late spring-early summer crop. They are kind of a cool weather crop but hold up to heat better than many other cool weather crops. If I were you I'd plant them today and see what happens. They may work out, probably will. If not, next time you know to start them earlier. It's one of those trial and error things.
You may be able to grow them in the fall. Even if I knew your weather and first frost or first freeze dates I wouldn't know exactly when to start them. I tried growing some cool weather crops in the fall when I was in Arkansas. It did not work out. I had to start them in the heat of August to give them time to mature. Cool weather crops generally don't like that kind of heat. Even if they germinate they cook. Plus by then the world was full of bugs that really loved that tender vegetation.
On the other hand, down here in South Louisiana I can plant when the heat breaks and have a good winter garden, including beets. I personally like the beets. My wife really likes beet greens. That's a win-win around here.
Are you familiar with beet seeds, they are kind of different. The seeds are in clusters. each globe in a cluster is a separate seed. I don't always get great germination and those clusters are big enough they are pretty easy to plant individually instead of just scattering them. I plant the clusters about 2" apart in rows about 3" apart, more of a bed than a row. Then I thin to where each one is about 2" to 3" from it's neighbor to give them room to grow. I use a short plank to put in the first row, then back that plank up about 3" to plant the next row. That's the only way I can control spacing. Not sure how Bay plants hers. She's generally more talented than me.
