If you live in the USA:
Despite all of the arising automobile safety technologies, there are just a few that are required by regulations. These mandated safety functions consist of Seatbelts, Airbags, LATCH child safety seat system, Tire-Pressure Display, Electronic Stability Control, and Backup Cameras. All-new vehicles will certainly have that tech and in addition, the NHTSA recommends the following Motorist Assistance Technologies:
FWD Crash Warning
Automatic Emergency Situation Braking
Lane Departure Warning
Whether you can ask the dealer to turn them off is dependent entirely on whether the manufacturer will allow them to do that. Generally the manufacturer is the one who allows the dealer access to scan tool tech that would be able to do this and what access they have varies by manufacturer.
There are things you can potentially do yourself including pulling fuses or relays (where applicable), disconnecting antennas (depending on your level of skill to get access), and asking an aftermarket shop to physically disable certain systems.
The main problem with this is, 1. It could void your warranty which may mean you aren't eligible for some warrantable repairs including but not limited to recalls. 2. You could potentially do some damage to systems yourself by accident that you would be on the hook for. 3. You will likely lose other features you paid for. This is of course dependent on how the manufacturer integrated the systems you want to remove or disable.
It may be a better idea to see what options you have to avoid paying for those optional features and make your decision based on what manufacturers allow you to remove them when you order the vehicle. This may be better for you than trying to drive a dealer vehicle off the lot. It will take more time though.
I think if I were you and I had to have a newer car I would try to buy a used car that doesn't have these features you don't want.