(a) Yoga with Adriene Mishler https://grokker.com/fitness/collection/yoga-with-adriene-mishler/6009c7453fa6704a3439b548
(b) Yoga by Candace Cabrera Moore Tavino https://grokker.com/yoga/collection/yoga-by-candace-cabrera-moore-tavino/5fffcbcadb8e8d4f07e52ad8
(c) Flow Yoga Beginner - Intermediate https://grokker.com/yoga/collection/flow-yoga-beginner-intermediate/60ce43f84cb7214269a7ea13

Hi - With apologies, here are two corrections to my prior message yesterday:
(a) Somehow I deleted some text in the middle of the message. Here is the missing text that should have been included: "Maybe try walking for a few days. Walking is a terrific form of exercise. Assess whether you still get nauseous from walking....."
(b) I noticed that you posted this message in the "yoga" category rather than the "fitness" category. Here are some rigorous beginner yoga flows that hopefully are mellow enough to circumvent nausea. Best wishes and good luck!

Congratulations on your commitment to self-care, and welcome to Grokker! Maybe a professional will see this message and chime in with wiser advice, but in the meantime here is the two-cents'-worth from a non-professional fellow Grokker user.
Maybe take a peek at the exercise guidelines from the Centers for Disease Control: https://www.cdc.gov/physicalactivity/basics/adults/index.htm
You'll see that those guidelines stipulate 150 minutes per week at moderate intensity (like brisk walking in their example one) plus two days per week of muscle-strengthening activities.
Iof exercise), and assess whether you still get nauseous from walking. If walking makes you nauseous, maybe check with a medical doctor for possible causes. (For example, last summer 2021 for a couple of months my head spinned when I exercised; that was caused by mild long COVID, which fortunately disappeared.)