I want to install a ceramic shower but don't know how to make the shower pan.?

Make sure you have a choraly liner down first. build a curb with 3 2"X4"s, with the 4" side down. the liner needs to run up the wall about 8" underneath your wallboard (durock ,densshield,) and also over the curb. Do not nail the wallboard below 12" from the bottom of the floor. Mix 4 parts sand to 1 part mason mix, make your mix stiff so you can put in the proper pitch. Make a level line about 3" from the liner around the wallboard. pitch your pan toward the drain about a 1/2". Make sure you allow for the tile and mortar thickness so that the top of the finished tile is the same height as the drain. This is a pretty complex job. You might want to call a professional. Either way .good luck.

What you are describing is a custom shower pan and really should be installed by a professional. Originally this was done with lead sheeting laid over the subfloor, over the curb, and up the walls about 8". More recently rubber matting was used. Most important is having this water tight pan properly done. it is all there is to keep water from getting where you don't want it to go. The newest technique is using fiberglass and resin to seal over the wall board and underlayment. Once again, professionally done. All are complex processes.

you can't buy a ceramic pan for that size. since its a new build your probably gonna wanna put a layer of concrete on the bottom along with drain, then apply your compound, ceramic and grout and sealer for the walls use green board which is used for shower areas won't get moldy then do the same thing you did to the floor on the base of the shower make sure you get non-skid tiles so it's not slippery

You buy the pan.