You can teleport players to entities and armor stands are entities so they're good markers for this purpose. Place an armor stand and name it with a name tag (such as 'pos1'). Then you can teleport the player with the following command.
/tp @p @e[name=pos1]
If you want to move the armor stand without having to replace and rename it, you can teleport the armor stand to your current position.
/tp @e[name=pos1] @p
If you don't want the armor stand to be visible you can grant the armor stand an invisibility effect with particles disabled for a really long time.
/effect @e[name=pos1] invisibility 99999999 0 true
If you wish to remove the armor stands you can kill them easily with commands
/kill @e[name=pos1]