Turkish's 29-letter alphabet (see Turkish Alphabet) is comparatively quick to learn — the real early investment is classifying vowels correctly, since that pays off throughout the whole grammar system.
Because İ/i and I/ı are genuinely separate letters and sounds (not a stylistic variation), practice them as their own dedicated pair rather than assuming familiarity with the Latin "I" transfers automatically — this is the single most commonly mismastered part of the Turkish alphabet.
As you meet each vowel (a, ı, o, u = back; e, i, ö, ü = front), actively note its classification rather than treating this as a separate "vowel harmony" topic for later — building this classification habit during alphabet study saves real time when suffixes are introduced.
Ç, ş, ğ, ö, and ü are the letters beyond standard Latin — learning them together as "the additions" rather than scattered among familiar letters helps you notice exactly what's genuinely new.
Because Turkish spelling is highly phonetic, you can start reading real short words correctly almost as soon as you know the letters — take advantage of this by reading aloud from the very first days rather than waiting until "enough" letters are memorized.
See also the reference page: Turkish Alphabet.
The dotted/dotless İ/I distinction — many learners assume familiarity with the Latin "I" transfers automatically, when in fact these are two genuinely separate letters and sounds.
It's more efficient to classify each vowel as front or back while first learning it, rather than treating vowel harmony as an unrelated topic to study later.
Ç, ş, ğ, ö, and ü — worth learning together as a set so you clearly see what's genuinely new versus already familiar.
Almost immediately — because Turkish spelling is highly phonetic, reading real short words aloud is productive practice from the very first days of learning the alphabet.