Question: My supervisor started the e-mail thread of welcoming me to the team/department. Several team members has already replied (including the boss of my supervisor so I'm extra nervous) with a brief but warm welcome message. I was wondering what is the best way to reply in this thread.

This is my first fully remote role so I am not that familiar with how it works yet.

Would a short reply like "Thanks for the warm welcome, I'm excited to be working with everyone and I'm looking forward meeting you in the upcoming weeks." or Should I be adding my professional background/main tasks of my role/hobbies/etc. ?

Answer: 
Since the position is fully remote, I think it would be appropriate to reply with:

* Friendly "thank you" as OP stated
* Your full and correct email signature. Follow the norms at your company, if everyone else has phone and title and pronouns, make sure your signature has those. If they just use a short signature, make sure your contact details are up to date in whatever your company uses as a directory.
* Specific to the remote role - Your general location and time zone. Languages spoken may also be valuable for international companies. This can open up opportunities to meet professionally for lunch or drinks with another remote worker in the same area. It also helps you and your new coworkers offset meeting times to be within sane hours for your local time zones.

The idea from @iBug to reply on the 2nd day is good.
> 
> "Thanks for the warm welcome, I'm excited to be working with everyone and I'm looking forward meeting you in the upcoming weeks."
> 
> 
> 

Your suggested reply is perfect. Stop fretting.