Unless you are looking for a specific guide, start with the first one and work your way through them in order (Excluding the Safe Mode option) until any issues you have been having have been resolved.
A lot of issues can be repaired by updating windows. This guide shows you the best way to update Windows; even if you haven't been able to get it to update before
This guide shows you how to run a SFC scan. This scan is the best way to identify and potentially repair any windows corruption
This guide shows you how to run the DISM scan. The DISM scan has the best chance of repairing windows as long as it doesn't run into any problems that don't let it complete
This guide will reinstall a lot of Windows built in apps. If one of those apps is somehow causing your issues, this guide should help you fix it
*Only select this guide if you believe your issues are caused by a program or windows service. If you believe your issues are caused by Windows corruption, skip this step and reinstall Windows