한국어 얼마 동안 공부 하셨어요?
How long did you study Korean?
앞으로 질문이 있으시면 (if you have questions), 꼭 알려 주시고요 (waaa... please translate : )...
앞으로 잘 부탁합니다! --- [u]거마워요!!!
If you have a question, definitely let us know
And we (ask a favor) of you in the future.
The favor 부탁 is pretty general... so it can be "listen to our lessons," "leave us comments," "use our site," etc. And its just like "be kind to us." in a very general matter of speaking!