You can read this from the IRS.
https://www.irs.gov/businesses/small-businesses-self-employed/starting-a-business
You also might want to consult a local tax/business professional to get you started.
You have not told us whether you are a sole proprietor or if the business is an Scorps, Ccorps, or multi-member partnership. The tax advice will be different depending on that information.
If you are a sole proprietor, you are self-employed, and will be paying self-employment tax for your own Social Security and Medicare, as well as ordinary income tax. You will be able to use online Self-Employed software to prepare your tax return, or any version of the CD/download---you will need to complete a Schedule C for your business expenses.
https://ttlc.intuit.com/questions/2926899-how-does-my-side-job-affect-my-taxes
https://ttlc.intuit.com/community/self-employed/help/what-is-the-self-employment-tax/00/25922
https://ttlc.intuit.com/questions/2902389-why-am-i-paying-self-employment-tax
https://ttlc.intuit.com/questions/1901340-where-do-i-enter-schedule-c
https://ttlc.intuit.com/questions/3398950-what-self-employed-expenses-can-i-deduct
https://ttlc.intuit.com/questions/1901110-do-i-need-to-make-estimated-tax-payments-to-the-irs
https://turbotax.intuit.com/tax-tools/calculators/self-employed/
Provide some details so someone can be more helpful. And...the suggestion to seek local professional advice was a good idea since you are new to starting a business.