A "legal separation" is a common request. There is no court order in Virginia that is titled a "legal separation." There is an agreement between the spouses that says how things are to be handled called a "separation agreement" or a "marital settlement agreement."
A separation agreement can resolve all of the issues in the divorce or it can handle some issues and leave others for the judge to decide. If you can only agree about some of the issues in your case, it would be wise to resolve those in a written agreement and then focus your energies on the areas where you don't agree.
Separation agreements must be signed to be enforceable. It is never a good idea to do your own agreement without some legal advice. The standard or generic forms found online or from a book may create unforeseen problems. You would be better off to make a list of points on which you do agree and give it to an attorney to turn into your separation agreement.
When a divorce is finalized, the separation agreement will be made part of the court's order. This is important because the obligations undertaken in the agreement can then be enforced by the court's power and a party can be sent to jail for failing to do things the agreement requires. A second part of a separation agreement is that some of the rights it confers cannot be changed by the court.
Child support and child custody issues can always be changed by the court. But an unqualified promise to pay spousal support may not be changeable by the judge.