In my mind, you could use both (others may disagree) although if you were going to require Print Sharpening, then you would need to use Classic (CC doesn’t have this yet).
Simply, Classic will give you more options but, using Lightroom CC, as long as the High Res file is in the Cloud (as opposed say to a Smart Preview synced from a Classic Collection) and you Export (Save To) Full Size, most dSLR photos should print okay (up
to a reasonable size).
It depends what the printer’s specifications are (if there are any at all), but most would adjust what you have supplied to your required size.
Anyone else's thoughts?
I understand that for editing photos to use in sosial media lightroom CC is the best.
That is very debatable. Lightroom CC only has a built-in service to share to facebook on the desktop. It can't send to instagram, twitter, flickr, etc. Classic can do all those things through publish services. Lightroom CC on iOS and Android can do a bit more but is very inflexible. So if you want social media and want some control, Lightroom Classic is actually a lot better. Lightroom CC is good for one thing only which is that your images show up the same (if everything works correctly) everywhere. Lightroom Classic is centered around a single catalog on a single machine. There are definitely ways to use both but they are discouraged by Adobe. I mix them up but you really have to know what you are doing.
But I also want to be able to send my photos somewhere to get them printed, both small and large. Can I export photos I have edited in Lightroom CC and send them to printing? In large scale aswell? Or do I have to use Lightroom Classic CC to be able to get the pictures printed to hang on the wall?
Yes, you can do this from CC but if you want the best quality Lightroom Classic is head and shoulders above CC in this area. The export options from CC are very limited in that you can't output sharpen, use a different color space than sRGB, layout your print using borders and such that Classic can do. It will do in a pinch if you just want to send a bunch of images to costco for 4x6 prints but if you want a service to make a good fine art print, Classic will give you much more flexibility.