Practice as a GST advocate

Yes you can work as a GST practitioner , if you are B.com , M.com , Inter CA or CA , you have to. apply on GSTN portal , and submit all required documents . you can log in on www gst .gov.in apply in registration . before you apply please read rule 83 of the CGST rules 2017 for more details , you will get all information on portal .

Agree with Prasad

Obtain knowledge of GST from various sources, books, videos, articles. Form a client base. Provide services based on your knowledge.

You can also become a GST practitioner as per Rule 83