I haven't been to Betis but Seville. Bought a ticket on their website, chose the seat (avoiding the ultras section) and printed at home. It was a Europa League game against an east European team so was relatively sedate. The stadium was ringed by snack stalls before the match - apparently it's a big thing over there. It was all fine. Probably not that different at Betis.

Seville wasn't the easiest place to get around but looks like there's a local train station near the stadium. Nice town; I especially liked the Metropol Parasol but I like that kind of thing. Have a great trip!