Shower p trap and vent advice

[Bid19123]

I am replacing a tub with a shower. There is a p trap in place which I cant get too. The shower drain will be 36 inches from this p trap. I have read it is not allowed to have 2 p traps in series so I will have to run the 36 inches before the p trap. I understand this may lead to smells over time but I see no other solution. My next concern is a vent; will the shower need one and if so where should it be placed. I have never seen a shower with a vent.

 

[FullySprinklered]

There's a lot of missing information there, but if you're doing ceramic tile, your guy can slope the floor to the existing drain. If you are going with a fiberglass or acrylic base with a drain cast in the center, good luck.