Hi,
1. Yes, you should show it as business income and pay tax on it.
2. Yes, you can deduct all business related expenditure from this income. Alternatively, you may also choose an option of presumptive taxation wherein directly 50% of your income will be deemed as your profit. However, this option is subject to certain conditions.
Further, there may also be requirement of registration under gst if the income exceeds INR 20 lacs in a financial year