You will have to manually enter any carry-over information from last year into TurboTax unless your accountant prepared the tax return using TurboTax software. In that case, you would be prompted upload the previous year tax file when you started the tax return.
The main things you need to add from last year would the basic business information (name, address, ID #, etc.) and the shareholder information.
You may also have to enter the prior year balance sheet information if it was required on the return (because sales were more than $250,000).
The program will prompt you to enter the pertinent information from your 2018 tax return as you work through it.