Who should I ask questions to?

I think some amount of load balancing makes sense; you want to get to know as many members of your team as possible anyways. It's also always nice getting multiple engineering perspectives - It's very helpful for growth. I also recommend asking junior/mid-level engineers for help as they'll likely be excited to help a senior engineer, and there's a good chance you can teach them something in return due to your seniority.

Another thing I want to add is how you thank people for answering your questions is really important. There's less of a chance that you'll feel like a burden if people really enjoy answering your questions due to your strong gratitude. People don't realize that thanking people well is a skill, and you can learn more about that in my video here: How To Build Work Relationships Faster - Giving Deeper Thanks

Here's some quick thoughts from that video on how to properly thank great helpers:

• Thank their manager and make sure that this is represented positively in their performance review
• Write a heartfelt thank-you note to them (i.e. a paragraph or 2)
• Tell them how much you appreciate them in person, ideally a 1 on 1 meeting

I also recommend my Effective Communication for generally good advice on better interacting with people: Alex's Guide To Effective Communication