As others suggested, look at letter you received and see if any information about setting up a portal account.
Not sure when you say can not be upright, but wheelchairs are available. Just ask when arrive.

As @bsrice mentioned, there may be questionnaires that can be filled out ahead of time. This saves time when you arrive. If not filled out ahead of time, the desk attendant will ask you to fill out when you arrive either via paper or on iPad. It is so much more efficient if do as much as possible ahead of time.

Also, pack all your medications so when nurse initially meets with you she can enter into your medical records.

Two other items,
- they will ask for your medical insurance cards to scan it. You probably have already provided info to Mayo, but desk attendant may ask for them to scan it.
- If this is first appointment, they may also ask if want to sign a "Authorization to Disclose Protected Health Information to Family and Friends" form. Due to HIPPA, they will not talk to anyone with out your approval. So if you want any of your children to have authority to talk to a provider, you will need to sign one for each person. Just need to know their full name and birthday.

Safe travels and good luck at your appt.

Laurie