How do I find the information I need from last years taxes to input into this years taxes

If you've been using TurboTax Online, you can follow these steps to get a previous year return:
https://ttlc.intuit.com/questions/1900748-how-do-i-get-a-copy-of-a-return-i-filed-in-turbotax-online

Another option to get your previous year return is through the IRS. More details are available in this FAQ: https://ttlc.intuit.com/questions/1901218-can-i-get-a-copy-of-my-tax-return-from-the-irs