The Wiccan alphabet (or the Theban alphabet more commonly) is fairly easy to learn and is only really a case of memorizing what letters the different symbols represent. Each of the symbols represents an English letter, although some letters aren't represented, as there isn't enough symbols to cover them all as it was likely created based on a much older more basic alphabet. It is commonly used by Wiccan practitioners for use in their spell books, which they call books of shadows. It is used primarily as a cipher or code system so that most people wont be able to decipher what they find should they happen to see a spell book or coded message that you don't want them to be able to read.
Although the exact origin is unknown for certain, we do know that it first appeared in relatively modern print in Henry Cornelius Agrippa's Third book of Occult Philosophy written in 1531. There are other sources than maintain it was first seen in Johannes Trithemius' Polygraphia written in 1518. Although there is some dispute over this and it remains a hot topic in some Wiccan and historical circles. While it does resemble some ancient languages there has never been any other documented evidence or findings of its exact existence or even substantiation of its use in any other cultures around the world.
In the book Agrippa attributes its creation to Honorius of Thebes (hence the name Theban). This despite the fact that apparently he also notes Pietro d'Abano as the creator in some of his other works, who lived some 200 years previously to Honorius depending on the source you research. It was likely only used as a code for concealing and coding messages rather than as a written language for common use in itself. Nevertheless Honorius seems to have gotten the credit for it in the main as it is sometimes refereed to as 'the runes of Honorius' or the Honorian Alphabet although Theban itself is not an actual runic alphabet.
It has no other significant magical or symbolic meaning other then this to the wiccan followers really, other then it looks more of a magical form of writing and can be used as a means of encoding private spells or messages from most people. It was originally introduced to Wicca by the founder of modern Wiccan beliefs Gerald Gardner, and isn't inherently a Wiccan alphabet per-se. Although its use has been adopted for a lot of Wicca practices and in a lot of Wiccan texts. It may also occasionally be used as a substitute for the much more complex and historically sound ancient Celtic or Saxon runes that are sometimes inscribed on jewellery or for spell casting.
After it passed into use for spell casting rather then for use in coded messages alone, it was adopted by a variety of different practitioners, although this was before modern Wicca had been founded. Similar to other magic symbols the Theban alphabet used to be used to ward away evil spirits and to put curses on people. Although modern Wicca tends to avoid these areas of magic if it can.
Also there is another alphabet sometimes used by Wicca practitioners called the alphabet of the magi. It, like the Theban alphabet uses symbols in place of the letters, and was invented in the 16th century. It is similar in appearance to the Wiccan alphabet, although generally isn't as widely used for Wicca.
Learning for most people is only a question of practice. As you use the letters more and more you will over time become familiar with each one, to the point where you can read them as easily as you can read normal text. There are very little recourses for the learning of the Wiccan alphabet as there is for most other languages. Although some Wiccan stores have now started carrying language tapes to help you learn. The best way other than this to learn is to practice with the people you intend to use the letters with. Whether that might be people you want to send coded messages to or the other members of your Wiccan group.
Being tested on the letters and by making simple coded messages for each other you will learn the letters very quickly. Often in as little as a couple of weeks you wont need the list of what each letter represents when reading a message of performing a spell. The symbols themselves can be widely found online on almost all Wiccan and code breaking websites, although can't be written on a standard keyboard, which is why I haven't listed them here.