1. Company GST details (F11 / GST Details): GSTIN, state, registration type.
2. Stock item 'Laptop': HSN 8471, GST 18%.
3. Create a sales invoice to a Delhi customer (CGST+SGST) and one to a Rajasthan customer (IGST); compare.
4. Print/preview the invoice and check GSTIN, HSN, tax breakup.
5. Open GSTR-1 report and resolve any 'Uncertain transactions'.