GST and Income Tax for double income

Hi Team

Had a query. 

I am a salaried guy for now but planning a side business of e commerce / dropshipping. I do not wish to create a company. Will be paying income tax anyways.

Current taxable income is 5.5 Lacs

Q: What will be Income Tax slabs (old regime)?

Q: How to file ITR?

Q: Can I register on GST as individual? Do not wish to create a company right now

Q: Other tax liability (if any)?

Q: Any other legal limitations to consider?