What are some of the best ways for someone with no background or experience in linguistics to learn how to read and write another language?

What means “another language”? If you cannot decide which is this another language, then try Esperanto which is the easiest language to learn. There are lots of sites where you can learn Esperanto for free. (Please do not pay to learn Esperanto, beyond buying a textbook or a dictionary) I have spoken in Esperanto in 31 countries with people from about 100 countries.