If you want to explore maps/practice jumps alone you can start a local LAN server by starting the tutorial and entering the following cmd into console “switchlevel obj_xxxx”.
OBJ_Bridge
OBJ_CanaryWharf (Underground)
OBJ_Map_6 (Dome)
OBJ_Trainyard
OBJ_Victoria (Terminal)
OBJ_Whitechapel (Chapel)