I have competed at novice level (the second level in Australia) and trained to Elementary (3rd level). I trained the mare from a green bush basher, all by myself, and with very little instruction.
We jumped 1.2m while schooling and used to regularly compete at the 1m mark, occasionally 1.05 in second rounds. And schooled over 1* (and a few smaller 2*) cross country obsticals, however only ever competed in one introductory level event.
We have placed in lots of different showring classes at local shows. They are lower level shows, however still get very good riders (the people who do the curcuits for a living). And we have done quite well against them.