And if you want use some useful Plugins (after mastered the classic tools) πŸ˜„
try the Didier Bur Projection where the last icon can extrude a line(s)! β˜€

Of course you can move draw them in any 3D angle direction! πŸ€“
So any junction will be a game's boy! πŸ˜‰
If you move all edges of a plane surface(s) that is an "open Tube" Push Pull Multiple with a direction! β˜€

junction.jpg