u have to run a non-official server (sv_official 0) in order to use custom stuff.
you can load maps by either e.g. /devmap obj_xxx (with cheats enabled) or /map obj_xxx (no cheats)
in order to getr all weapons u have to use the
allweaponspack and pout it in the tcetest folder.
are u using a seperate pc to host the lan server or are u trying to host and play ont eh same pc? if you have an extra pc for hosting u should maybe use a proper server.cfg. i can do that for u if u tell me what u need (settings,...)