When you install an operating system on a new machine, the virtualisation , by default, is off in the BIOS . Depending your hardware you need to log into the BIOS and enable it, based on the hardware manual. In my ASUS x470, first you enter the BIOS.There from the "Easy Mode" you need to enter into the "Advanced Mode." There again from the menu select Advanced. From options down there you can see the "CPU Information" and when you click on it and expand it then you have a set of choices. You need to enable SVM Mode.
Otherwise, from the Virtual Box you receive messages such as this "AMD-V is not available (VERR_SVM_NO_SVM)."
Also in Windows operating system you might need to uncheck Hyper-V enabling options in Windows 10 through the "Apps and Feature" in Windows setting. Right click on the start icon-bottom, left of your screen, and at the top of the menu select "Apps and Feature." On the right side of the dialog click on "Programs and Feature." On the next screen dialog, on the left side then click on the "Turn the Features on and off," then find the Hyper-V manager and uncheck the options under it.
On the contrary you might like to use Hyper-V, Microsoft hypervisor for your virtualisation then check those two option . Microsoft hyper visor is not as simple to use as the VirtualBox but some people might prefer it. To enable it you can use the PowerShell (opened with administrator privileges) with the following command:
Enable-WindowsOptionalFeature -Online -FeatureName Microsoft-Hyper-V -All
If you use Microsoft hyper-V then you are not able to use VM virtual machine or VirtualBox.
To create a virtual machine in Hyper-V go to "Start" icon left click on it and then click on the "Windows Administrative Tools" and select Hyper-V Quick Create, and follow the instructions you find thereafter. You can use your local downloaded sources such as the "iso" images of Linux distributions or other desired operating systems or the suggested sources, default on the Hyper-V, for direct download and installation.