I agree with Padraic completely regarding making use of the library for introductory books. Similar information is also available online. Videos can be even better for casting and those are available at many libraries as well, perhaps even through interlibrary loan if your local branch is lacking.
Let me emphasize in your introductory reading and practice, that you learn about leaders and tippet and tying the blood knot since you will be working with those every single trip and multiple times during each trip.
Avoid plastic or metal line-to-leader connectors that alledge you don't have to tie a nail or needle knot (for attaching the leader to the line). There are some inexpensive tools that make tying the nail knot fast and easy, so get one of those if you have difficulty.
Do not attempt to cast a weighted fly or a leader with split shot the same way you do a dry fly.
There are very few technique books that repay perusing over the years. The one that stands out is Joe Humphreys's Trout Tactics, updated and expanded edition. While it doe not go into tackle in very much detail, it does cover dry flies, wet flies, nymphing and streamers in detail. Most important, If you go after trout or char, the chapter on water temperatures is a must.
A mentor who has some equipment he or she can lend you and who can show you the ropes is really the ultimate advantage for the beginner. Such a person can often be found at a TU or FFF chapter.
