As an Amazon FBA seller (sole proprietor) based in Orange County, CA, what are all of the taxation requirements I need to comply with legally?

yu need to fiel yoiur return once the amounton Sch C linr 29 / 31 is 400 or exceeds $400 and also need topay seca tax aslongas the amount on sch se line 2 / 3 is also $400 or exceeds $400;howeer, Individuals, including sole proprietors, generally have to make estimated tax payments if they expect to owe tax of $1k or more when their return is filed; You don?t have to pay estimated tax for the current year if You had no tax liability for the prior year;You were a U.S. citizen or resident for the whole year;Your prior tax year covered a 12-month period, if you didn?t pay enough tax throughout the year, either through withholding or by making estimated tax payments, you may have to pay a penalty for underpayment of estimated tax. Generally, most taxpayers will avoid this penalty if they owe less than $1k in tax after subtracting their withholdings and credits, or if they paid at least 90% of the tax for the current year, or 100% of the tax shown on the return for the prior year, whichever is smaller.but many small biz owners actually do not pay estimated taxes since penalties are minimal aslongas their tax liabilities are not very high.