If I am a sole proprietorship, can I file once a year with my personal tax or do I still need to file quarterly?

[xmasbaby0]

There is no such thing as filing quarterly tax returns, even if you are a sole proprietor.   You file ONE tax return---one Form 1040 -- per year.   You can make estimated quarterly tax payments to avoid a big tax bill at tax time.

If you want to send in quarterly payments:

https://turbotax.intuit.com/tax-tools/calculators/self-employed/

https://www.calcxml.com/calculators/self-employment-tax-calculator     (non-TT site)

https://www.irs.gov/pub/irs-pdf/f1040es.pdf

https://www.irs.gov/payments