"Pied Beauty" has no regular meter. Instead, Hopkins invented "sprung rhythm." In this case, the name says it all. "Sprung rhythm" is like a spring, or more accurately, many small springs scattered throughout the poem. The accents and downbeats are concentrated together. The rhythm consists of small explosions of energy. Often, the grouping of accented syllables results in the cramming together of meaning as well. A perfect example occurs in line 4:
Fresh fire-coal chest-nut-falls.
Hopkins literally fuses words together in order to have the maximum amount of meaning and accents using the minimum number of words. The rhythm is characterized by stops and starts. Another way that Hopkins creates strong accents is by using alliteration everywhere. There is alliteration in (almost) every single line. "Sprung rhythm" is the big takeaway from Hopkins's poetry.
"Pied Beauty" does not have a regular form. Its genre, on the other hand, is a hymn. Hymns are religious songs of praise and prayer, and this poem takes its cues from the Book of Psalms in the Bible. The poem has two stanzas, the first with six lines and the second with five (assuming you count the final two words "Praise Him," as their own line). There are not a standard number of syllables per line. However, look at the way that each group of three lines is indented like three stairs going down. The poem has a rather complicated rhyme scheme, and lines with the same indentation tend to rhyme at the end. The scheme goes: ABCABC DBEDE. Then the last line "Praise Him" is set apart with its own indentation far to the right. It almost looks like the concluding "amen" of a religious prayer.