I need help transferring the 5 returns I prepped on the 2017 software to the 2018 software. One transferred over but no other returns seem to be available?

Hopefully you have 5 different tax files saved ... one per person ... and you did not use the same tax file for everyone. 

Do you have the 2017 tax file on your computer?  It ends in .tax2017.  You need that to transfer into 2018.  First thing you do is start a new return and it should find all your 2017 files and ask if you want to transfer them.  

Here's how for Mac:

https://ttlc.intuit.com/questions/1901265-transfer-last-year-s-return-into-turbotax-for-mac

Here's how for Windows:

 https://ttlc.intuit.com/questions/1901506-transfer-last-year-s-return-into-turbotax-for-windows