What is william hazlitts advice to his son in on conduct of life

Here is a good quote from the text that reflects his advice:

You are now going to settle at school, and may consider this as your first entrance into the world. As my health is so indifferent, and I may not be with you long, I wish to leave you some advice (the best I can) for your conduct in life, both that it may be of use to you, and as something to remember me by. I may at least be able to caution you against my own errors, if nothing else.