Where and how was the poet wandering?

The poet does not say in this poem precisely where he is when he is out wandering. He compares himself to a cloud floating "o'er vales and hills," which perhaps suggests that he, too, is out among the hills. Certainly, we know that when he comes upon the array of golden daffodils, he is somewhere in the depths of nature, because the daffodils are "beside the lake, beneath the trees."
It does not seem as if the poet expected to find such a beautiful show on his wanderings, so we can infer from this that he was not walking with purpose. On the contrary, his wanderings seem to be a matter of habit. The poet, Wordsworth, was well known for his fondness for country walks, which he often embarked upon with his sister and his fellow poet Samuel Taylor Coleridge.
In the final stanza of the poem, we see a second sort of "wandering" indulged in by the poet. Here, he revisits the array of dancing daffodils in his mind. He is not physically out in the natural world, but he can go back to what he saw in his mind whenever he wants to and draw sustenance from the memory.