Can I get turbo tax for 2014, 2015, 2016, 2017 for small business? I need to do prior year taxes? Thank

TurboTax does not support tax years prior to 2016. 

Either use a local tax professional for those tax return or you can get free federal forms, schedules and instructions for prior tax years from the IRS at this website - https://apps.irs.gov/app/picklist/list/priorFormPublication.html

If you are an independent contractor or sole proprietor and has not incorporated your business then you can use a Schedule C to report your income and expenses.  Schedule C is included with your personal tax return, Form 1040.  Any of the TurboTax desktop editions, Deluxe, Premier or Home & Business can be used.

If you have incorporated your business as a C Corp, S Corp or are a Partnership then the TurboTax Business Edition must be used.  The Business Edition cannot complete a personal tax return and can only be installed on a Windows based personal computer.

Go to this TurboTax website to purchase, download and install on a personal computer one of the prior year, 2018 thru 2016, desktop editions - https://turbotax.intuit.com/personal-taxes/past-years-products/

I HIGHLY recommend you seek local professional assistance to file these old years ASAP ... they may be able to get the penalties & interest waived or reduced since they are significant at this point.