Arabic rewards a clear order of operations more than most languages, because skipping ahead — vocabulary before the alphabet, dialect before Modern Standard Arabic — tends to create problems that show up much later.
Spend your first one to two weeks purely on the 28-letter alphabet and its pronunciation (see Arabic Alphabet) — not vocabulary, not phrases. Reading real Arabic script from day one, rather than relying on Latin-letter transliteration, pays for itself many times over later; unlearning transliteration habits is harder than never forming them.
Once letters are solid, build a working vocabulary of common, everyday words — numbers, family terms, basic verbs — learned with audio from the start, since Arabic has several sounds (see Arabic Pronunciation Guide) that are much easier to learn correctly early than to fix later.
Introduce grammar (sentence structure, gender, basic verb conjugation) once you have enough vocabulary that the rules have something concrete to attach to — grammar studied before vocabulary tends to feel abstract and doesn't stick as well.
Modern Standard Arabic is understood everywhere and is the right foundation for nearly all learners. If you have a specific reason to prioritize a dialect (family, a specific country), decide that deliberately rather than picking up dialect vocabulary accidentally and inconsistently.
Expect solid alphabet literacy within a couple of weeks of daily practice, basic conversational ability within several months of consistent study, and genuine reading fluency and grammar command over a year or more — Arabic is a long-term project, and treating it that way from the start avoids the discouragement of expecting shortcuts that don't exist.
See also the reference page: Learn Arabic.
Learning the alphabet fully before vocabulary, rather than relying on Latin-letter transliteration — skipping this step creates habits that are much harder to unlearn later than to avoid from the start.
Modern Standard Arabic is the standard, recommended starting point for nearly all learners, since it's understood everywhere; prioritize a dialect only if you have a specific, deliberate reason to.
Basic conversational ability typically takes several months of consistent study; genuine reading fluency and grammar command takes a year or more — Arabic rewards a long-term, patient approach.
It's better to avoid this — relying on transliteration early creates a dependency that's harder to break later than to simply invest in alphabet literacy from day one.