No - relax SWA is ok, fun and happyness. If you have a child 4 or under you can preboard "immediate family" this dosen't mean aunt or uncle or nana and papa however. This does mean mom/dad and siblings. When you check in online 24 hours prior you will be able to print your boarding pass and it WILL have your priority on it A, B or C.
So - if you don't have a child 4 or under then definately check in online. If you do then let your family check in first or check in for them ie, nana- papa etc.
Then get to the airport a normal time, enough to allow for checking luggage and getting through security. You CAN'T line up hours early from most airports as there will be a flight ahead of yours using the queues. So get to the airport on time - be ready and hang at the terminal. If you are preboarding they will preboard wheelchair/disability first and then young children. Don't even line up if you have preboard you don't have to! Then A then B then C will board. I lined up in A when others started we were about 4-5th in line and sat in a row of three close to the front, wonderful!
It really isn't to complicated and it really isn't a 'cattle call'. We did SWA for the first time from Philly to MCO and it was just me and my dd's 8 and 10. My 8yo was sooo afraid of sitting alone but we got A passes online and it would not have been an issue even if we didn't line up.
I worried for nothing so I hope you won't.
TJ