Companies like TurboTax can import data like W-2 if its available to them, but I believe entering the 1099-MISC is a manual operation.

While there is nothing wrong with estimating your 2019 tax bill and paying it by January 15 to avoid penalty,

there will only be a penalty if your underpayment is under $1000 OR you have already paid the IRS 90% of your 2019 final tax liability OR 100% of your 2018 (prior year) tax liability.

See: How do I estimate my taxes when I have only 1099 income?

As you have had W-2 wages, if the Federal withheld exceeds what you made in 2018 and it sounds like you earned $0 in 2018 you should be fine. If you had interest or dividend income in 2018, you should pay enough just to avoid penalty.

If your earnings are done via contracting and still continuing, you are correct about paying quarterly estimated tax payments.

Do realize that most US states have state income tax as well so plan for that.

Given that IRS instructions for Form 1040 for 2019 tax year are not going to available under after January 15 you may wish to wait to file your 2019 Federal Income Tax.

Companies like TurboTax can import data like W-2 if its available to them, but I believe entering the 1099-MISC is a manual operation.

Generally you should be paying estimated tax throughout the year to avoid penalty.

From IRS - Topic No. 306 Penalty for Underpayment of Estimated Tax:

Generally, most taxpayers will avoid this penalty if they either owe less than $1,000 in tax after subtracting their withholding and refundable credits, or if they paid withholding and estimated tax of 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.

See: How do I estimate my taxes when I have only 1099 income?

As you have had W-2 wages, if the Federal withheld exceeds what you made in 2018 and it sounds like you earned $0 in 2018 you should be fine. If you had interest or dividend income in 2018, you should pay enough just to avoid penalty.

If your earnings are done via contracting and still continuing, you are correct about paying quarterly estimated tax payments.

Do realize that most US states have state income tax as well so plan for that.

Given that IRS instructions for Form 1040 for 2019 tax year are not going to available under after January 15 you may wish to wait to file your 2019 Federal Income Tax.

Companies like TurboTax can import data like W-2 if its available to them, but I believe entering the 1099-MISC is a manual operation.

While there is nothing wrong with estimating your 2019 tax bill and paying it by January 15 to avoid penalty,

there will only be a penalty if your underpayment is under $1000 OR you have already paid the IRS 90% of your 2019 final tax liability OR 100% of your 2018 (prior year) tax liability.

See: How do I estimate my taxes when I have only 1099 income?

As you have had W-2 wages, if the Federal withheld exceeds what you made in 2018 and it sounds like you earned $0 in 2018 you should be fine. If you had interest or dividends in 2018, you should pay enough just to avoid penalty.

If your earnings are done via contracting and still continuing, you are correct about paying quarterly estimated tax payments.

Do realize that most US states have income tax as well so plan for that.

Given that IRS instructions for Form 1040 for 2019 tax year are not going to available under after January 15 there isn't a way to fill your 2019 Federal Income Tax.

Companies like TurboTax can import data like W-2 if its available to them, but I believe entering the 1099-MISC is a manual operation.

While there is nothing wrong with estimating your 2019 tax bill and paying it by January 15 to avoid penalty,

there will only be a penalty if your underpayment is under $1000 OR you have already paid the IRS 90% of your 2019 final tax liability OR 100% of your 2018 (prior year) tax liability.

See: How do I estimate my taxes when I have only 1099 income?

As you have had W-2 wages, if the Federal withheld exceeds what you made in 2018 and it sounds like you earned $0 in 2018 you should be fine. If you had interest or dividend income in 2018, you should pay enough just to avoid penalty.

If your earnings are done via contracting and still continuing, you are correct about paying quarterly estimated tax payments.

Do realize that most US states have state income tax as well so plan for that.

Given that IRS instructions for Form 1040 for 2019 tax year are not going to available under after January 15 you may wish to wait to file your 2019 Federal Income Tax.