Hi Jason,
first, you may want to checkout/follow If You Were a DevSummit Newbie, What Would You Do? Since there will be some handy tips for the Dev Summit in general.
re: how to prepare. It sounds like you have some Python programming, at least enough to understand the general syntax (for example, the importance of tabs/spaces for program flow). If not, that might be good to review.
i would recommend looking at some of the proceedings and/videos of previous dev summit or UCs to get a preview of some of the sessions. Recent Proceedings There are other ways to view the videos, including videos.esri.com and the Esri channel(s) on YouTube. Pick a topic that you think you might want to attend and see if there is any topic that make know sense and see if you can at least figure part of that out.
I found that if there was something that was mind boggling for me in a session the first time I attended the dev, it was hard to obs orb the rest of the session. But no fear, there are other sessions, and a great bunch of other developers and staff that you can talk to too. And from what I understand, the videos will be available for a limited time for free...or you can purchase the recordsing (which includes a few mor)
if you like seeing the "road ahead" sessions, those are usually not recorded...so attend those if it's a priority.
if you can make it before the summit (sun/mon) take one of the focussed pre-summit classes. The cost is separate (but cheaper than a normal Esri class) and the class sometimes compress 3-days into 2, but you can get a crash course in, for example, for Python or Javascript. This helps you either eliminate some of the sessions from you todo list, or helps you get a jump start on the sessions and/or helps you form what questions you need to follow up on.
if looking at Python specifically, there are a few threads on geonet on getting started, and Dan P has some docs on differences between he pythons, etc. if I try to grab the link right now, my iPad my eat this...long... Response. But can get it for you if needed.
of course, what you focus on will depend somewhat on whether you are needing to custom Desktop (map/catalog) with Python 2.7, Pro with Python 3.x, ...or some of the other dev environments for those, or web development (JavaScript, HTML, Web App Builder developer or online, etc), the enterprise software (arcgis sever, Portal, Image Server, ...arcgis online portal), the various mobile apps, etc. It can be overwhelming, so trying to choose one or two topics to focus on might help., or you can hit all just to get exposure. Depends on your goals of course.
I also recommend picking out something that you know little or nothing about and checking it out. He last session I hit in 2017 was the ArcGIS API for Python which I didn't really think about before that. Learned enough in the session to get started playing with it after the summit. This year I'm taking the per-summit class.
Although a bit more technical/geeky than the UC, (and a bit more intimidating, or I was for me the first time...and maybe still), it's actually a smaller and a more laid back group. One of the nice things about the dev summit (and the forums for that matter) is to find that no matter what you are working on, and what level of developer or GIS-expertise you are, there are others that are in the same boat. Good to have the comaraderie ...and there is always someone (many in my case) that know more and are will to help/share.
But, the main thing is to have fun, chat with others and learn what you can.
Loking forward to it myself!
