As others have pointed out, learning the alphabet (or any writing system) really has nothing to do with speaking, it's only for reading and writing. Many people are fluent in a language, and are completely illiterate.
Learning the names and shapes of the letters of the alphabet is the first step, but the next (and critically important step) is learning to associate the specific sounds with letter(s) it represent - recognizing that those lines on a page have a function and value. The first step is called phonics, the second step is called phonemic awareness. Phonics teaches that the lines and squiggles have a specific sound value, while phonemic awareness is the ability to recognize that words are comprised of little chunks of sounds. Put the sounds together in a certain way, and you have a meaningful word.
The next step is learning to combine those sounds into words, and to decode written text into sounds. I've kind of lumped that into one big step, as there are numerous smaller steps such as blending, segmentation, deletion, print skills, sight words, rhyming, syllabification, etc.
Reading consists of four main components - alphabetics (a combination of phonics and phonemic awareness), fluency (the ability to string words together accurately and at a fast enough pace to support meaning), vocabulary (knowing what individual words mean), and comprehension (understanding what the text as a whole is about).
There are various systems of teaching reading - some internet searching will provide you with various books and methodologies. It also helps to have someone give you one of the various assessments, to see what your strengths and weaknesses are in regards to those four main areas. Someone might for example be able to read fluently, but not know what many of the words mean, indicating a weakness in vocabulary. Or, they might know what all the words mean, but have trouble stringing them together to support comprehension, indicating a weakness in fluency.
Generally, the order of progression is alphabetics, fluency, vocabulary, and comprehension. Unless you can pronounce the words correctly (alphabetics), then your fluency will struggle. Even if you don't know what a given word means, with strong alphabetics skills you'll still be able to pronounce it.