Many people seem to be under the impression that most -- all? -- formal learning follows a stratified model, where there are beginners' classes, and then corresponding classes for each "standard". This approach gets drummed in at school, but it is not the only way.
In the system that I teach, we learn from each other, and we learn by teaching. It is no coincidence that we are part of a "Federation of Instructors"; through our training we learn to teach.
It is an old saying that you never learn something as well as when you have to teach someone else, and we harness this truth through pair practice. After the instructor demonstrates a technique -- for example a throw-- on an assistant, pairs of students -- typically of mixed standards -- practice it. One throws; the other is thrown; then alternation ensues. The raw beginner tries to grasp the basic movements; a more experienced student refines the details; a seasoned practitioner figures out how to apply the technique to partners of all shapes and sizes. The more experienced partner may give the junior partner tips (occasionally vice versa), and they both pick up details from each other.
So it is neither necessary nor desirable to have everybody of uniform standard in our classes. Variety is the spice of life ... and of training.
Remember: You can start any time. Next step: Keep practicing.