1) Disable lock screen ads. To do this you will have to turn off Windows Spotlight. Go to settings - personalize - Lock screen. Change the setting to picture or slideshow instead of Windows Spotlight. Also switch off the option to show fun facts and more. The more is usually the ads you keep seeing.
2) Shut off Start menu suggestions. Go to settings -personalize - start and switch "occasionally show suggestions" to off
3) Disable Office notifications. Go to settings - system - notifications & actions and choose what notifications you want to turn off.