As far back as I can remember (...and cs6 is definitely going back some years), the newly installed version won't touch the existing version. For almost all purposes, they will act like completely separate programs.
I'm seriously annoyed. When I was looking at buying for my classroom, I was looking at CC. Then somewhere along the way I ended up with CS6. That's old! Should I care? Does it matter? What's the deal with the whole cloud thing with CC? Does that make it more of a hassle? Does buying CS6 mean you own it vs. CC which seems to be something you rent?
I could be wrong, but Adobe stopped supporting CS6 in July of 2015......................as of Jan 9 of 2017, Creative Suite was no longer available for purchase from Adobe.
I myself ran a boxed version of CS6 Extended which I bought outright and owned up until a week or so ago and then I finally upgraded to CC 2017. I mention this HERE.
CS6 was stable on my old iMac but from everything I had read it was going to have problems on the newer computers. I bought a 27" Retina Disp iMac running Sierra so I finally threw in the towel. I like having the newer version of Ps so I can finally avail myself of some of the newer features that CS6 lacked.
I won't advise you on what you should be using, that's strictly up to you. I will do my best to answer any questions though.
I just needed a simple PS for my classes that won't go too deeply into it, but use it more as just image editing software. I remember CC being this new format where you pay for a license for a certain amount of years, and then I assume, it no longer works. I think that's an awful model, so if getting stuck with this old version of PS means that at least I can use it forever, that would be a big consolation. Can anyone explain the difference in terms of long-term use? Also, if Adobe doesn't support CS6, how might that be an issue? Maybe it's good because I won't keep getting prompts for updates.
I remember years ago I was at a school where I was using Fireworks for like 8 or 9 years without ever getting a new one. That was nice!
With CS6, you could use it forever if needed and it was running properly on your system. Any support you would need would be that which you could scrape up on the internet.
CC is service that gives you access to the Adobe software of your choice delivered in a monthly or annual subscription. The program is loaded to your computer and works just as you had uploaded it from an install disc. The program will be supported and updated for as long as the subscription is maintained. If and when you allow your subscription to lapse, the program will no longer function.
Based on what you've communicated here today, I think CS6 is exactly what you need.
Back to your original question.
I have design standard 5.5 loaded on my laptop. What happens if I don't uninstall it and load cs6?
Not totally sure from your posts if you have actually bought yet or are just exploring the options - I think you are saying that you have already purchased CS6?
If not then you could also consider Affinity Photo which is receiving some positive reports as a creditable alternative to Photoshop - it is a one off purchase, not subscription. I believe it is about £50 here in the UK. From your description of your needs it could suit you well. You can check it out here https://affinity.serif.com/en-gb/photo/
Yes do check out Affinity, it just like photoshop in lots of ways and no subscription costs...You can have your cake and eat it too.
I was on 2017 and loved it till recently......it started having issues that wouldn't fix itself. So one day I got really peed off with it and divorced it once and for all. Went back to the best one I have ever used 2015.5.... Now back enjoying doing what I do.
Moral of story..don't settle for second best, get Affinity and one of the previous versions mentioned and go back to having fun.