If you want to access your Windows PC (or Laptop) you can use software from Microsoft (Microsoft remote access). Here are the steps how you can do that.
On the MAC: got to your Appstore, search for “Microsoft remote desktop” and install it (it’s free)
On your Windows system: got to Settings and “enable remote Desktop”
After enabling you can add your Windows system to Microsoft Remote Desktop on your Mac. It’s even possible to work with 2 Monitors. It is very fast!
The easiest way to realize a remote access from your Windows PC (or even a Tablet) to your Mac offers Parallels.com: https://www.parallels.com/products/access/
It is an affordable solution: $19 a year. If you already subscribed Parallels on your Mac, you’ll get this in your package (Parallels, Parallel Tools, Parallel access)
It works like this: you’ll have to install additional software on your Mac to make this happen.
If you want to access your Windows PC from your Mac: there’s also additional software for Windows.
It works with your Parallels account: so it should also work when you’re not at home (I’ve not tested this option)
After logging in with your parallels account, you can simply start the connection
It’s even possible to work in full screen mode.