technology

If you use an external keyboard are you able to get to the BIOS screen?

on the BIOS screen are you able to use the arrow keys on the laptop keyboard (confirm not just the del/f11 key/timing)

in the BIOS menu ensure that the keyboard layout is set to US, if it wasn't then try using it after changing it back

in bios look for an option to enable/disable the keyboard and trackpad hardware (this will effect the laptop keyboard only), this is vendor specific so there may not be an option and I don't know what it will be called for a microsoft surface if it's there

If you have confirmed this is hardware issue then that is pretty hard to diagnose from a forum. Consider if you really care about the on device inputs or whether you are happy to just use external keyboard/mouse.

Not to overstate it but repairing laptop hardware can be fidgety with some risk of breakage of bits like bevels and such that effect the finish of the device. You are definitely capable of fixing it if you want (even if you don't think you are) but I am getting a vibe that you are not interested in learning this as a skill in which case this would be a reasonable time to take it to a repair shop since you've eliminated the "I should of known that " possibilities.

Laptops are very model specific here so I can't tell you much about a surface 7. If you are going to do it yourself then find a tear down video of the specific model and watch it through a few times. Don't try to figure it out as you go. As someone else mentioned check for loose connections on the hardware, if that is the issue then this should be a quick fix. If you have to replace the keyboard then you can look for replacement parts on aliexpress/ebay/amazon and possibly get non-genuine for cheaper than ifixit or the original supplier but you probably will notice a quality difference and some chance of it not fitting back in as easily as genuine.

If the ifixit kit you are referring to is the screwdriver kit then you can find similar ones on aliexpress for much cheaper (the screwdrivers are lower quality but you won't notice unless you use them a lot, the other stuff is pretty much the same. that said if you find a good deal on some wera screwdrivers and decide to splurge you won't regret it in the long run).

The main things you would need are just:

• Precision screwdrivers (you probably know someone you can borrow these off, if you don't then you should buy some anyway it probably won't be the last time you need them)
• spudgers/plastic prying tools (you can possibly use improvised tools like plastic takeout knives but they are cheap enough you might as well just buy some made for the job)

Possibly need if it's a really annoying model

• Heatgun/Hairdryer
• epoxy

Nice to have:

• isopropyl alcohol (from hardware store)
• anti-static wristband. you don't really need this you just have to ground yourself by touching some metal connected to ground
• silicone mats. you just need a clear workspace that doesn't have any static hazards and somewhere to keep the parts and screws you take out organized
• compressed air from a can or aircompressor to clean the dust out