Basic question regarding level measurements

Hi all.?ÿ?ÿ

I'm not a surveyor and have no knowledge of surveying, but I'm looking at a project which will require me to take mAOD level readings at specific points.?ÿ I need to know the GPS coordinates of these points.

Am I right in thinking that I need two of these (one to act as a ground station, and one to move around to the different points)?

https://www.unmannedtechshop.co.uk/product/emlid-reach-rs2/?gclid=CjwKCAjwydP5BRBREiwA-qrCGmY-exq7RYvJZg68U5sPwmLHbBR9PD4M9Rmz3fmK1B3bJQQ0O2iMxRoCb2sQAvD_BwE

Many thanks