Student Growing Chinese Herbs

I am a current Chinese Medicine student and have labored many jobs in landscaping, at a botanic garden and organic farm. With my studies and past job interests, I have the desire to begin a learning garden for our school.
I found a woman in New York, who has given us free seed, but we can't seem to get the garden off the ground with the seeds. Me and some students got some seed to emerge, but every perennial died off.
We were successful with annuals. I'm trying to choose the plants that I think would do best in our area. We are in Denver, CO, Zone 5 and at 5300 feet altitude.
I feel overwhelmed, confused, discouraged and feel like I've never worked with plants when it comes to this project.
What advice to you have for me?

This is a hard one to respond to, as I may need more data. While you can germinate the seed, you can't have them continue to grow? At what stage do the seedlings die off? There is a term called "hardening off," where seedlings are put outside at the 4" stage to adapt to the cold and release specific hormones for survival. That is usually in May.
If they were dying off prior to that stage, I would look at the medium you are using to grow them. That is most likely your problem. Another could be your seed source, with some form of genetic problems. Also, your altititude is high enough to have light possibly be the first killer. At 5,300 feet, not many perennials get the wavelength of light necessary and cannot continue to grow. You are over one mile high in altitude.
See what the problem is? I don't enough data to pin down what you problem are. Also, I noticed you are thinking you have a "black thumb." That alone (attitude) will kill plants. It is amazing how our thought alone will influence outcomes. Change your medium and change your seed source and see what happens next. Also love your plants and give them all the confidence you would your children.
I wished I could help you further, but without the data... How else can I help you?