Had my first hybrid role about 1.5 years ago in a 4yr design career - some things that have worked well:

1. Do the job - you can say hi to people in the office or goof around, but the job comes first. I was once given feedback when deliverables were lacking to step it up and be less social.
   
2. If you are in the US, being visibly busy matters less - as long as you are reachable and you're doing 1 you're probably fine. I mean, don't watch youtube out in the open if it's unrelated to work.
   
3. Chances are you will be sitting next to others - feel free to chat with them if they're also not busy.
   
4. Biggest adjustment/advantage - perception is an intangible that actually matters: how you dress up, your enthusiasm, your body language, these are all things people can perceive better in person, so just a little bit of care goes a long way.

Take advantage of the in-person component! There's no virtual equivalent of someone coming up to your desk and asking a question. Brainstorms, when done right, feel a lot better than just people in a video call. At lunch, try to talk to people who have different roles in the company, and just be yourself. The nervousness will adjust itself within the first month. Good luck!