I'm thinking of registering my small business but I'm not sure if I should wait till the next year starts.

[xmasbaby0]

And what is your question?    If you have a sole proprietor small business, it is a "disregarded entity" on your tax return.   You will have self-employment income and pay self-employment tax for Social Security and Medicare, along with your ordinary income tax.   You will be entering that self-employment income on the same tax return on which all of your other income is entered.

https://ttlc.intuit.com/questions/2926899-how-does-my-side-job-affect-my-taxes

https://ttlc.intuit.com/turbotax-support/en-us/help-article/form-1099-nec/1099-nec/L5qTsBiSe_US_en_U...

https://ttlc.intuit.com/community/self-employed/help/how-do-i-report-income-from-self-employment/00/...

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

[xmasbaby0]

Since you did not ask a question---we kind of have to guess what your issue is.   Are you referring to structuring the business as a C-corps or S-corps?   If that is what you mean, then if you do that, you will file a separate tax return for the business and you will need special tax software or professional tax help.   You would need TurboTax for Business which can only be used on a Windows computer.   You  would also need "regular" TurboTax to prepare your personal tax return.