I like Matt`s suggestion.
Get a recommendation for the local county extension agent and/or ask at the local feed store.
Most likely the feed store will have a good mix that works well for where you live.
Here is some information for Tennessee:
https://utbeef.tennessee.edu/forages-forage-species/
For how to do the planting, unless you know or can hire someone, Here is how we plant our feed plots.
We use a broad cast seed speaders. After putting down the seed we use our mule or our golf cart to run over the field so that the seed makes good contact.
It is best to do this when rain is predicted unless you have a way to get water to the seed.