Anyone out there do competitive dog agility (have some questions)?

I have a female Sheltie who just turned a year and is awesome at agility. This is my first time doing agility with any dog. I've done a lot of AKC obedience though. She is definitely ready to AG-1 for UKC but she still is learning weaving so she can't do AKC yet. What is a good way to practice weaving at home without spending an arm and a leg on equipment? Could I just practice with cones? Also, my instructors are really big on "distance control" (I think that's what it's called) and it is so confusing to me! They have me do front cross-overs and it is so awkward to me (I'm not a very cordinated person to begin with!) but they say it's necessary to learn if I want to go to higher levels with my dog. Right now, my Sheltie barks at me alot when we're running the course. Of course, Shelties DO BARK TONS but they said that she's partially doing that because she's looking for me to instruct her. Basically, the dog is way smarter than me! How can I not get so frustrated? (Cont'd)