A new Standard is issued every third year. C++11 and C++20 had numerous big improvements that seriously improved the whole coding experience. C++14 and C++17 had few wholly new features, but relaxed many restrictions. C++23 will not be a big release, although probably it will get "reflection", making it easier to write and to use serializer/deserializer libraries, and a comprehensive networking library.
Most people pick up the new features a little at a time by reading blog posts or watching conference presentation videos. An hour or two a week, over as many weeks as you need, gets you up to speed fast enough.