You can migrate to GST. If all your documents such as PAN, Aadhaar etc. have your name with first name of your father, then you have to go with same name.
To change name first you need to change your name in your PAN and other documents.
Digital signature certificate or DSC is an encrypted code generated using your id (PAN), it is used to sign computer generated documents or application.
You can google it, E-mudra provides online facility.