How do you use fluxbox in OpenBSD

I recently installed OpenBSD on my sparc64 workstation and I wanted to use fluxbox for my desktop environment. When I install it and try to start it it gives a error saying "couldn't connect to xserver passing null display" I looked online an saw something about editing the .xsession file but it is not there I only have the root user because I didn't set up any other users but I did reinstall it once and added a user with but the file still wasn't there. I want to make fluxbox start automatically after logging in. I am very new to UNIX so please help. Edit: I actually also wanted to try icewm but it gives the error "cant open display: . X must be running and $DISPLAY set."