cheap ways to find things
You need to be searching garage sales and dumpsters. I've found most of my tanks at garage sales, the want ads, thrifty nickle or the like, there are ussually people giving away tanks and if they are going to throw it away they ussually set it beside the dumpster. Look at apartment complexes suring the spring and fall when people are moving.
Soak everything in a bleach solution and let it dry in the sun. Do a leak test outside and re-caulk everything if you need to.
Make good with your petco and petsmart employees. You can get freebees thrown your way. But only if they think you know what your doing. They get a lot of animals abandoned that need good homes.
Study so you can spot deals and items that you can use in your local garden center that can be repurposed. Its amazing what you can do with pvc.
Start with 10 and 20 gal tanks with native frogs that you can buy cheap and play with there set ups.
A lot of plants that parents and grand parents have can be great in terrariums, pothos ivy and spider plants, mondo plants, monkey grass. Its not hard to find someone that doesnt use fertilizer...
um...does that help?