Freshmen aren't in a lottery I don't think. Just order them before the deadline (second week of June I think) and you'll be fine. Tickets are available in April (forgot the exact date). To get into Block O make sure you 1) Get on to hangonsloopy.com EARLY (read: first few days) and 2) While buying the student tickets, specify that you want to sit in Block O. Its that simple.
As far as student tickets for out of conference games (Miami, Texas, SD St.) they become available in the late summer. You buy each ticket separately for $27 a pop, tickets for students are on a first come first serve basis. Get online as early as possible and you might be able to score some good seats. Thats how I got 11AA row 2 for the cinci and marshall games last year (got up at 7:00 AM and hammered the website). My guess is that tickets for the Texas game will be in tight supply for students, but hopefully they alot a certain number for students for each out of conference game.