This has nothing to do with Creative Cloud.
Your camera is too new, Lightroom 5.7.1 does not have the ability to recognize new camera's raw format.
You can purchase Lightroom 6.5 or later, and import the RAW into Lightroom 6.5 or later; or you can use the free Adobe DNG Converter version 9.5 or later and import the DNGs into Lightroom 5.7.1
Easiest and fastest is to convert your files to DNG using the free DNG converter.
The other option is to by an upgrade to LR6 witch is the current perpetual license LR in line with LR CC, the creative cloud version of LR. Only features that have been added to LR CC after the initial release of LR 6 are not available to LR 6 users. Camera Raw file formats are still updated and supported for new cameras.
The subscription model requires you to have an internet connection every 90 days. But it may be, that this could be a problem in your situation. I cannot judge that, but I suppose, that there is a possibility for you to access internet for other uses during that time period.
dj_paige's answer was, in one way, better than the instruction I eventually got through Adobe chat when I needed help looking for the 5 to 6 upgrade package. At least he/she recommended going straight to version 6.5 or later. Chat got me to the version 6 upgrade, but failed to note that the Sony A6300 wasn't supported by 6.0. So, I went through all the download and set up only to find that my camera still wasn't supported. Another session on chat plus another session downloading got me the latest upgrades. I just can't believe that buying the upgrade from 5 to 6 didn't include the upgrades. The chat agent should have at least told me that I'd have to go ahead and do them separately.
I just can't believe that buying the upgrade from 5 to 6 didn't include the upgrades.
If you have purchased LR 6, you do indeed have the ability to upgrade to Lightroom 6.5 FOR FREE. There are two seperate downloads and installations to wind up with Lightroom 6.5, first you download and install 6.0; then you downloadd the 6.5 update and install.