In the first stanza, James states that there is always a a safe place to go when you get really stressed out by what's going on in the world. He gives examples of things that have a haven or safe place. Then he talks about when your heart is at rest then you should forget about what's bothering you.
Then he talks about how there is no sorrow in your safe place and the sound of life you should block out so that you are calm. He gives examples of calm soothing sounds.
After he talks about how caring for the things they care for now goes away and do things the way you want as long you're in your safe place.
The most important piece of literacy in this poem is metaphors. James describes a lot of things that are just like safe havens and they are applied to objects that can't literally happen.
It was important for him to put those in the poem because it gives the poem more meaning. It helps the reader understand what he is talking about.