Candidate Master is a rank after Expert and before Master that represents a smooth transition between these two ranks. Its meaning to the community is that you're more than a competitor and you're invested in the platform. People will now recognize you more and take you more seriously. Of course, you'd expect that purple color you got gives you more perks. Well, look no further because I've written some stuff that may interest you, that's accessible once you become CM. ­

Getting to Candidate Master is no joke. My first ever Codeforces competition was Round 885, which was more than two years ago. Given my background in CP I got to Expert in only 9 competitions, but then I stayed for over a year in that layer because Codeforces competitions simply have different tasks from local competitions or olympiads. The first half of the tasks on almost every competition on Codeforces don't require any standard algorithms to solve. No segment trees, no Dijkstra, no treaps. The most complex algorithm you're gonna use is the sort function and the most complex data structure — map. But this comes at the cost of advanced logical thinking and problem-solving.

However, that advanced problem solving can be mastered through solving more tasks. Go on every Div 2 competition you can and try to solve ABCD fast, or solve ABCDE. Once you participate enough times, you'll eventually reach Candidate Master.

Quoting How to interpret Contest Ratings by EbTech:

Welcome to Division 1! As a pre-requisite to the esteemed title of Master, you are deemed eligible to prove yourself by competing alongside the best of the best, on the toughest problem sets that Codeforces offers. Professional whiteboard interviews cease to scare or even challenge you; now they're just an opportunity for you to flex over interesting problem discussions.

Once you've reached Candidate Master, you'll start to notice some new changes to the behavior of the Codeforces website. The most notable change is that you can now add tags on new problems! There are still a couple of requirements too, like the problem has to be fresh from the oven and you must solve it first.
If you meet the requirements, the No tag edit access text will change to Add tag. Clicking it will open a dropdown where you can select a tag to add. You can also remove existing tags by clicking the × on the tag.

The other thing I've noticed is that now you can report ("Complain") a comment/blog you've downvoted. An icon will appear on the right of the comment, which you can click to open a modal to complain for the comment/blog.

Even though these two perks are interesting, the main reason I've been pushing myself to CM is that some communities require you to have at least CM (or 1900+ rating, same thing now) to join them. Two of them are AC and GF. These are essentially communities of Div 1, where the best of the best (seriously, AC has at least 7 LGMs) are gathered and discuss everything. I'm new in these communities because I got to CM just yesterday. To unlock the server, simply use the TLE bot with sending ;handle identify Username, where Username is your CF username. For the verification process, the TLE bot will give you a task to submit a solution that results in Compilation Error. You have 60 seconds to submit.

But, after all that, it's still not over. The golden Master rank can't wait to decorate your name. Luckily, consistently solving E is also enough for becoming a Master, and the span of the Candidate Master rank is only 200 rating! You should get to Master in no time, but only if you can solve ABCDE fast. Really fast. You should solve A in less than 2 minutes, B in less than 10 mins and C in 15-20 mins. You sould be able to solve D in the next 30 mins, and solve E until the end of the competition, preferably before the 1h30m mark. Also, at every moment of the competition make sure to have the first two unsolved tasks read. It will give you more opportunity to solve one, because oftentimes C is easier than B.
Disclaimer: I made these numbers up

From CM you officially meet the requirements for rated participation in Div 1. Try to go on as many Div 1s as possible, because soon you won't be able to get rating from Div 2s, and you need to adapt to Div 1's environment (harder tasks). Global rounds or Div 1+2s are easier than most Div 1s and Div 2s, so try going on them. But don't go on those only, because they are rare, and you'll need much more time to get to Master.

Overall, if you've reached CM, you've reached a giant milestone — but that doesn't mean you should stop. The divine orange medium awaits you. Good luck on your journey.