Can someone help correct my poem to make it better or add dashes, ellipses, semicolons anywhere to add effect?What is Poetry? Poetry is like...

This is a lovely poem. You've written in free verse without any consistent rhythm or meter, though you do have a pattern of long and short lines. You lead off with "poetry," which is a dactylic ( / ^ ^ ) rhythm. One of the more prominent lines, "When I read / it aloud / it sings / to my ears," is an anapestic rhythm with a pause introduced even though the required comma marking the pause has been neglected ("aloud, it"). The pause acts as one of the unstressed beats of the third foot of the lines tetrameter. The pause is one of the elemental components of English poetry and it is often overlooked where present or not given consideration during composition. This line is immediately followed by one in trochaic ( / ^ ) pentameter. All-in-all, your free verse poetic structure seems sound and, moreover, carries musicality with it, which is one of the chief qualities of poetry. So, I have no suggestions to make on these particulars.

However, your punctuation works against your meaning instead of facilitating it, so modifications are advisable in this quarter. The first portion of your poem can serve as an illustrative example for the rest.

Line 1, change the period after water to an em dash (--).
Line 2, use enjambment and omit the comma after turns.
Line 3, leave as is.
Line 4, as in line 1, change the end period to an em dash.
Line 5, add a comma after the adverbial wh-clause ending in loud ("When I read it out loud [comma]").
Line 6, leave as is.
Line 7, same as Lines 1 and 4, change end period to em dash.
Line 8, leave.
Line 9, divide into two lines with a line-break between best and in; follow best with an ellipsis: "But if you try your best ... / In the end you will be left feeling impressed."
Line 10, change end period to em dash ("Poetry is the sun rising--")
Line 11, same as line 10.
Line 12, change the spelling of seeking to sinking; add an ellipsis between day and sinking: "It slowly fades at the end of the day ... sinking off into the horizon."
Line 13, leave as is.
Line 14, change the end comma to a semicolon ("flexible ;") because the two lines are separate sentences yet closely related to each other (a comma is incorrect for these same reasons).
Line 15, leave.
Line 16, change end period to em dash.
Line 17, leave.

You can now apply this model to the rest of your poem.