One of the hard things about colour film processing in the past was that the chemicals had to be in a narrow temperature range: nowadays that is relatively easy to do by 'simply' keeping them in a warm bath kept in the correct range via sous vide equipment.
Generally if you're doing analog B&W photography at any non-small volumes, it's probably cheaper to get the gear to have your own darkroom and at least process the negatives yourself. Once you see the shots, you can then perhaps take them to a printer if you don't want to do that yourself.
The 'default' process for processing colour film is C-41:
* https://en.wikipedia.org/wiki/C-41_process
You can get B&W film that uses the same process:
* https://www.ilfordphoto.com/xp2-super-35mm
One of the hard things about colour film processing in the past was that the chemicals had to be in a narrow temperature range: nowadays that is relatively easy to do by 'simply' keeping them in a warm bath kept in the correct range via sous vide equipment.
Generally if you're doing analog B&W photography at any non-small volumes, it's probably cheaper to get the gear to have your own darkroom and at least process the negatives yourself. Once you see the shots, you can then perhaps take them to a printer if you don't want to do that yourself.