From coustumer guest to coustumer

Can i use costumer guest and do this as ordinary costumer?
- change status to none guest
- Put in new billingadress and shippingadress

I use var customer = EngineContext.Current.Resolve<Nop.Core.IWorkContext>().CurrentCustomer; topick up current guest costumer. But how can i easy insert new addresses to this coustumer?

How can i create object Billingadresses and Shippingadresses  to _workContext.CurrentCustomer ?

Don’t know what you are trying to achieve
If set ordersettings.anonymouscheckoutallowed then it still creates a customer and billing address record in the database anyway
Can’t you use that functionality and adjust the records for your purposes after the order is created?
There is also plugins to automatically convert the above data to customer records
See https://www.nopcommerce.com/extensions?searchterm=guest