It's been a while since I set up my NAS on a Win 10 PC, but let's assume that it is not too disimilar.
I assume your PC and NAS are on the same network, e.g. 192.168.1.x
On you NAS, I assume that you have set up one or more users, each with an access password that you use when you access the NAS with a browser. I further assume that you have set up a number of shared folders. You will, again I assume, be able to grant access rights, read, write, etc., to each of those folders to the NAS users.
If you are using Windows 10, you will need to turn on Network Discovery. There are plenty of instructions to do this online, but go to Settings/Network and Internet/Network and Sharing Centre/Advanced Sharing Options/ and make sure the Network Discovery option is selected, together with the Automatic setup of network-connected devices. This is for the current Windows user profile only. Hopefully, you will then be able to navigate your NAS files with Windows Explorer.
There are then two other ways to access the NAS with windows. First is to create a Network Share, or second to map a network drive. If you open File Explorer to the This PC level, there should be options for both these on the menu bar. If you are asked to provided credentials, then these will be the username and passwords set up on your NAS. Hope this helps.