The poet yearns to go to the Lake Isle of Innisfree because he is seeking peace. On Innisfree he would be able to live alone in a small cabin, growing beans and keeping bees.
He explicitly states in the second stanza that he would find peace on Innisfree. He describes peace as leading a slow-paced life in a natural environment. He imagines feeling peaceful as he hears the crickets singing, sees the stars (midnight's "glimmer") and experiences evenings full of "linnet's wings."
In the third stanza, he contrasts this natural idyll with what he has been experiencing: standing on "roadways" or "pavements" (sidewalks), which suggests he has been living in a city or a busy, congested area. This is what he hopes to escape.
The poet is part of a long lineage of writers seeking peace and refuge in nature, simplicity, and solitude, away from the stress and crowds of cities and modern life.