1. Sit down with your DCT to discuss your goals, THEIR goals for you, and what you'd like to get out of your training year. Sites can really vary w. how much they tailor the experience to you. I felt very fortunate to have active and involved supervisors, but this isn't always the case.
2. It goes quickly, so make sure to take your vacation time, mind your self-care, and take advantage of any training opportunities that may help you down the road. I attended a ton of "brown bag" didactics across various departments during my intern year, and I found it informative and also a nice way to get to know the day to day things other colleagues are seeing.
3. Post-Doc/Fellowship application time can vary greatly, so know when you nee to start thinking about getting LORS, etc. Neuro usually goes first (Nov/Dec to early Jan apps are submitted), but many other openings don't start getting posted until the Spring. Your post-doc/fellowship plans should be an on-going conversation with your DCT and supervisors.
4. Enjoy your outside of work time. I moved to a new part of the country, to a new city, etc. I didn't have much time or money...but I still did a lot of local things and tried to take in some of the culture. Being able to decompress like that made the work week much more manageable.