The original GPS receivers in the late 80s and early 90s did not have maps. And they used LCD screens. The one I owned by Lowrance required 6 AA batteries. Not AAA. Not rechargeable. Optional power through a cigarette-auto cable, but that's not helpful when on foot. It burned through batteries like crazy.
I owned this one:
https://web.archive.org/web/20231104153749/http://retro-gps.... (Lowrance GlobalNav Sport) 160 x 160 pixel display. It weighed 2 pounds with batteries.
It provided latitude, longitude, and heading.
Thought I would use it hiking but it was just too big to be anything but a toy. You inserted a cartridge, specific to your geographic area, if you wanted it to display names of towns/cities (data on the cartridges):
https://www.ebay.com/itm/314936082464
It did have "waypoints" (lat/long bookmarks, essentially) that allowed you to plot a line as you traveled. It could tell you how far you were to different waypoints you'd previously entered. IIRC, it had a serial connection for waypoint download to a PC. People tried sharing waypoint series -- "routes" -- but it just never really had much success as I recall. It was just too cumbersome.