I don't understand why this sentece is not
"Mi pretas lerni interesajn ideojn."
Why is pret- here as an adjective between the verb chain?
On the basis of my first language, I could interpret this as either 'ready to learn' or 'done (with) learning, through with learning'. How could I express the latter thing in Esperanto?
If you've finished the course, you could say "Mi finis lerni". If you abandoned it, you could say "Mi forlasis la kurson" or "Mi ĉesis lerni".