I don't see a way to save my progress from the pause menu, as we used to be able to do in previous Fallout games. So how do I save my progress if I haven't gotten to a checkpoint? Is there a way to force a checkpoint save?
Fallout 76 relies purely on automatic saves. I am yet to find a list of things that trigger said saves, but as far as I can tell, they appear to just be timed. However, with that said, you can force saves through fast travel.
With that said, there are ways in which players can predictably make the game save their current progress. By far the easiest method involves fast traveling. When you've made progress in the game but haven't seen a save notification recently, pull up the map and fast travel to a new destination. The C.A.M.P. should suit these purposes particularly well. After fast traveling, the game will save the player's current location, which effectively saves all of their progress up to that point.
In case anyone is still wondering about this, everything is 'saved' server-side in real time like any purely online game.
It's clear that people misunderstand how the "save" system works. The only time progress can be "lost" is if the server crashes before the buffer is committed as happened in the early days of the game at times. In the case of story quests there will be notifications that you have passed a part of that storyline but again the game saves as you play.