Leaving from Liverpool

Welcome, Stranger. My name is John Higham. The year is 1858 and I am 31 years of age. You see me here in London where I live with my family; my wife Sarah and our sons, William, 9 and Joseph, 6.
Thankfully, unlike others at this time, I am in the employment of Messrs. J & E Robinson, working as a builder. However, I like to pride myself that I have some learning beyond that of a labourer.
Please join me and advise me on whether I should emigrate and how to go about it.