Grats Mike, best of luck!

At ATL, all five runways are parallel and typically 2 of the 5 are used for departures (the two ones closest to the ramps on the north/center complexes, 27R and 26L). There's also the option to do "full triple departures" and depart off runway 28 as well.

The RNAV departure setup is extremely efficient and can be configured in multiple ways. The most common "departure split" involves south and east departures departing 27R and the north/wests off 26L. This allows for each direction to have a dedicated path immediately off the ground, with sufficient divergence to launch aircraft simultaneously/with just same runway separation. Bad IMC makes things less efficient, due to the lack of tower-applied visual between arrivals and departures on the same complex.

The ground sequence is accomplished by alternating the direction of departure - a south, then an east, then another south. If all departures are going the same direction, then they can be sequenced by individual departure gates/fixes. (There's four SIDs per direction.) The parallel taxiways can be used to accomplish this, with one direction on one and the other on the other, and then ground just alternates each into into one line to the runway. This is more difficult in east configuration, because as I explain below you can't really have departures going the same way toward the runway on the parallel taxiways with arrivals coming. As such, people might be held at the ramp for the sequence or might even be taxied eastbound on one taxiway then westbound on the other.

In west flow, for arrivals:

On the north complex we have the taxiway V loop, so arrivals taxi there "around" the departure end of the runway, simultaneously as aircraft takeoff, and then eastbound on the parallel taxiway to the ramp. Since all departures will also be taxiing eastbound to the runway, and the V loop spits the arrivals out at the westernmost ramp, regardless of parking there's not gonna be a nose to nose conflict.

On the center complex, it's the same deal with arrivals crossing the departure runway (27R) at a few taxiways that will result in them only going east to the ramps.

In east flow:

On the north complex, arrivals still taxi on V but it gets more complicated. There are two parallel taxiways between the ramp and departure runway, and usually the farther one is used as a westbound taxiway and the closer one as an eastbound taxiway to alleviate conflict, since the arrivals are going east to parking and the departures are going west to the runway.

Since there's no taxiway V equivalent on the center complex, we depart airplanes at intersection M2 and arrivals cross the runway behind the  departures uninterrupted. However, the same issue with east flow comes into play as with the north complex, with one taxiway treated as westbound (departures) and the other eastbound (arrivals).

Good luck David!