Your request doesn’t make sense, actually. [disclaimer: At least it doesn’t make sense in music as talked about in the English language, I’ve just learnt it’s different in France and other Romance countries]
A, B, C, etc. determines the pitch of the notes in your music. Especially, they can be used to denote the 8 pitches that make up the C major (or A minor) scale. In Western music we usually work with 12-tone equal temperament, which means that we have 12 notes that are ‘equal distances’ away from each other (in terms of sound waves, the difference in frequency between one of the 12 notes and the next is always the same ratio). To get these 12 pitches, we assign sharps ♯ or flats ♭ to the notes A, B, C,… Some notes sound equal (like C♯ / C-sharp and D♭ / D-flat), but there is a difference between using sharps or flats that is given through the function of said note in the context of the music.
Do, re, mi, etc. do not determine the pitch of a note, but determine the function of the note. A piece of (Western) music usually is written in a certain key (not as in a key on your piano, but as in a pitch on which the music is “based” or “rooted”). Do will always refer to this key (called the tonic), re, will always refer to the second note (the supertonic) in the appropriate scale for the key, etc. For example, if we’re working in the key of C major, then do = C, re = D, mi = E, etc., but if we work in E minor, then do = E, re = F♯, mi = G, etc…
Finally, sheet music is yet another system, where notes are graphically represented on a scale, so it uses neither do, re, mi nor A, B, C.
You don’t need to know the theory behind the music you’re playing, but it makes it a lot easier to communicate about music, in some ways to perform it (since it might help in understanding the function of the notes in the music) and definitely in composition / analysis (since you’ll be able to describe why you like something, and not something else).
However, for a beginner, I would recommend to ignore music theory for now, and simply work with the idea that A, A♯ / B♭, B, C, C♯ / D♭, D, etc. refer to certain keys on your piano, and focus on pressing the right key at the right moment.
Final comment: if you want to learn the thing, don’t go searching for ‘training wheels’, but learn the actual thing. The faster you’re able to read scores and tackle chords, the easier it becomes to learn piano. It’s easier to learn Korean correctly if you start with learning the alphabet and then do everything with the Korean symbols, than if you start with learning things using crutches (such as ‘phonetic’ transcription of Korean in Latin letters) and have to switch back later.