If you are already a JAWS user I believe you'll find NVDA very easy to use, as there are many, many commands that overlap. There are some that don't, and getting those clear in your mind can take a bit.
My introduction to NVDA was through using it as a surrogate for JAWS when I was tutoring JAWS. The Virginia Department for the Blind and Visually Impaired was not about to buy me a license, and often my testing and digging required more than 40 minutes, so I started using NVDA when I wanted to do certain things "at my leisure."
While the transition is not absolutely seamless, it's really not all that difficult, either.
Brian - Windows 10 Pro, 64-Bit, Version 20H2, Build 19042
Any idiot can face a crisis. It's the day-to-day living that wears you out.
~ Anton Chekhov