If you have 2 Macs, you can get to the other one by using Screen Sharing. Just go System Preferences > Sharing > Remote Management. From there you can choose the type of access the remote user will have. You can also limit it to just one user or allow all if you have multiple users.

To access the desktop from a remote desktop, just open up a Safari browser and enter in the URL box: vnc:// Substitute the IP Address of the remote desktop that you want to control remotely. I works on Chrome as well. Wished I did this earlier.

There’s no need to purchase any software. They’re already in the OS.