As soon as my windows was set up on a new system, i installed LinuxMint dual boot and not looked back, so I am with you kinda scared to boot in to windows.
I think you can turn off ads as part of the set up process, once I bypassed the sign up to MS garbage, I wasn't really in the mood for any more of their nonsense.
I am more worried that windows will detect dual boot and somehow try and fix the boot sector and break dual booting,
I have a USB stick with a rescue distro on somewhere, so you reminded me to check and make sure it is updated.
@zleap yes, be careful. If you run into problems with Windows overwriting your boot record, I recommend having a USB key hand with this on it close to hand: https://sourceforge.net/projects/boot-repair-cd/files/latest/download (used it a few days ago to quickly resurrect a friend's highschooler son's dual boot laptop - Linux Mint used almost exclusively, Windows largely ignored)
@killyourfm