Michi ~to you all (道 〜to you all)

Your heart toward, reach (imperative) (×3)

届け is the bare imperative form of 届く ('to reach') — used like a wish or a prayer addressed to one's own message: 'May this reach you.' Common in song lyrics; gentler than the more forceful 〜なさい imperative.

Mostly as-usual, that corner (path) if-turn

いつも通り (literally 'in the usual way') is a fixed phrase. Pairing 通り (どおり, 'as / according to') with various nouns: 予定通り ('as scheduled'), 約束通り ('as promised').

Crowd into slip-in

人波 (literally 'people-wave') is a poetic noun for a crowd treated as a tide — surging, pulling people along. Standard literary alternative to 群衆.

One only (topic) had-remained, your voice

Your smile face, if-see, surely (tag), understand right?

Verb-past + ら is one of two conditional forms with 〜たら ('if/when'): 見たら ('if/when I see'). More concrete and event-based than 〜ば. でしょう ('right?') invites confirmation.

Heart (subject) immature even, with-that good

未熟 (literally 'not yet ripe') used both for fruit and people. 未熟者 ('immature person') is a humble self-description: 'I'm still learning, please bear with me'. The line accepts that immaturity.

Look, there at (topic), important person (subject) is

And then, walk path (path)

歩む is a more literary/elevated verb for 'walk' than 歩く. Often used metaphorically for life-paths: 人生の道を歩む ('walk the path of life'). The song's title 道 ('path / road') ties to this verb.