Cartridges/Tapes/Disks

You don´t load ROMS. You insert the cartridge in your Commodore 64 and starts it by TURN ON or RESET your Commodore 64.

If you mean tapes or disks, then read this:
For tapes, type "LOAD" and then Press Play On Tape, and after the loading type "RUN".

For disks, type LOAD"*",8,1 and after the loading type "RUN".