The easiest way how to fix error "cannot be loaded because running scripts is disabled on this system. For more information, see about_Execution_Policies" is to run this before you run your Powershell script:
Set-ExecutionPolicy -Scope Process -ExecutionPolicy Bypass
So, what's going on here. At first, we set the -Scope parameter with Process. We are saying that this set of execution policy is just for this process and in the next session, we get the error again. The -ExecutionPolicy parameter with value Bypass means that nothing is blocked.
But maybe we want to be able to run scripts forever and we can do that by execution:
Set-ExecutionPolicy -Scope CurrentUser -ExecutionPolicy Bypass
So, we have unblocked all scripts running by this user.
Of course, there are different ways how we can set Execution policy and I can recommend you Microsoft doc About Execution Policies for more details.