Me and my friend are just began to the game,can we both use a tent for storing?And also,where should we build a tent?What should we do after building a tent?
Level your character or read books until you can get to 100% Outdoorsman skill.
Go to Gordon's Gas Station and get the Ranger perk. This allows you to make a SAFEHOUSE instead of a tent.
Once you have made your safehouse, use 3 wood on the campfire in order to make a map. Have your friend read the map.
Now you two are sharing a safehouse with a workbench inside.
But Seki's suggestion is valid, all the same.