Welcome from San Diego.
There are so many ways to go. You can build a ground up rifle, or get one off the shelf and modify as you go along. I see you have a thread about that going and I’ll bet you get some decent feedback there. Either way, take the time to research and plan it out. Not all parts play well together and you’ll want to know up front that not all 308 AR’s are AR-10’s and there’s a few different platforms out there that don’t intermix. Head to the build section for some inspiration from what others on here have cobbled together.