Help downgrading to Windows 7  

Welcome to the forum. Down grade from what? If it's win10 is it a new installation or upgrade if it's upgrade you can role back for 30 days. If it's a new pc before you do anything you need to know if drivers can be downloaded for 7 often there are no drivers for 7 as it's no longer supported.
Why do you want to install a system no longer supported?

You will need to check that the device will support the older OS, many major manufacturer's are no longer developing drivers for Windows 7 on Newer equipment. There may be generic base drivers available depending if the laptop is made for the business market, or you can manage with basic drivers from the individual components makers.

The best thing is to check if Lenovo ever supplied the exact model you have with Windows 7 Installed - obviously if this is so then the drivers should still be available but you would have to source them from Lenovo yourself - check the support pages for your model

The touch pad drivers may be easier to find than most, as the major manufacturers tend to "buy-in" touch pads rather than design their own ...

The following is a Wiki entry that may provide a start point - Touchpad - Wikipedia

Synaptics are the big manufacturer's favourite but if all else fails you can get USB touch-pads that may work for you. there may be details in the device manager as to what is fitted

Trick is to save the registry before trying any test driver install and restore original before the next - this should keep cross contamination to a minimum, ( a system image is even more reliable of course)

Worth checking in bios if there is a touchpad setting called something like "basic".

Have you got drivers for new things like usb3 which arnt supported in 7