I agree with Curtis on the recordings being high quality and well worth the cost. For the Developer Summit this year, they posted all the videos on that sight, (last year they only did 50), so you can check a few of them out right now. Some of the sessions are similar to what will be at the UC, so if you are deciding between two sessions, and find it on the site, you may be able to scratch it of your time conflict list.
The conference center is pretty spread out, I.e. Lots of walking, so besides whe ring good shoes, you may want to make sure you aren't having to go from one end to the other side each time. I have not looked at the Event app yet this year, but each year it has been improving, and there are layouts and maps to the rooms.
What I do is mark all those I am interested in (conflicts included) so if one is overflowing or I can't make it in time, I have a backup plan. They usually also have a room or too (usually room 20 I think) that may remotely broadcast a selected popular/overflow session.
It is great that you are planning ahead, since it is too overwhelming to do it day-of, but keep in mind that you may change your interests and priorities based on the plenary and/or other sessions. save some for possible follow up in the showcase (vendor and software "island" area).
One trick I do if I will be there on Friday, I look at the few offerings on that day first, which may free up an earlier slot. Btw, I know many leave early or skip the closing session, but many times there is interesting news and feedback, with questions asked by users and answered by staff. I've even seen announcements changed or at least reconsidered based on user feedback/pushback at the closing session. Just my thumbs-up for the closing session.
I know there are several threads for tips, for othe new and experienced attendees, I would check those out too. There may be some additional tips. Main thing, have a plan, but remain flexible.