2008 - 12 years ago? Or is that a typo an you mean 2018?
TurboTax online and e-file for 2018 ended on Oct 15, 2019. 2018 (and earlier tax years) can now only be completed using the CD/download software installed on a Mac or Windows computer. The return must be printed, signed and mailed.
2016-2018 software can be purchased here:
https://turbotax.intuit.com/personal-taxes/past-years-products/
2008? Why do you need to file a 2008 tax return from 11 tax years ago?
Or did you mean 2018?
To complete and file a 2018 tax return using TurboTax you would need to purchase, download and install on a personal computer one of the 2018 desktop editions from this website - https://turbotax.intuit.com/personal-taxes/past-years-products/
A 2018 tax return can only be printed and mailed, it cannot be e-filed.
Well Here are some blank forms & instructions for 2008
1040EZ https://www.irs.gov/pub/irs-prior/f1040ez--2008.pdf
Instructions https://www.irs.gov/pub/irs-prior/i1040ez--2008.pdf
1040A https://www.irs.gov/pub/irs-prior/f1040a--2008.pdf
Instructions https://www.irs.gov/pub/irs-prior/i1040a--2008.pdf
1040 https://www.irs.gov/pub/irs-prior/f1040--2008.pdf
Instructions https://www.irs.gov/pub/irs-prior/i1040--2008.pdf
2008 Tax Tables https://www.irs.gov/pub/irs-prior/i1040tt--2008.pdf
Publication 17 Tax Guide for 2008 https://www.irs.gov/pub/irs-prior/p17--2008.pdf