You select the film, lets just say B&W for the moment as with colour slides, there is no give, what you take is what you get. You pick a film, Iford Delta, FP5...etc first then you develop it after you took a photo.
There are also technique in developing (push and pull), by purposesly over expose and under develop and vice versa, or develop a B&W film using colour chemicals for funky effects. There is also the mixture of chemicals you can play with, the concentration, then the time you spent developing it in the chemicals.
Then it comes to print, you choose a type of paper, gloss, matte, the tone (serpia, whites), and then you do you cropping in the enlarger. Where you can expose it for different lengths to adjust contrast/brightness. You can also do the dodge and burn with your hands, it is all very analogue, you literally wave your hand or a piece of card over the print under the light.
To remove spots you can do it after the print is out of the machine/chemicals with a paint brush.
The whole process can be done in about 2 hours if you have an print instead of the chemical/trays/hang dry. The bit that takes up most time is the developing and hang dry the negatives bit, you don't want it to dry to fast as it will curd up instead of flat.