It is overwhelming to me and it doesn't sound like you enjoy gardening.
You may not cotton to this, but I would hire a landscape design person to come out ...take a look what you got there..advise what you should lose and what you should keep....because it is all hidden in the overgrown stuff. Explain what you are interested and willing and able to do yourself. (or not ) and take it from there. The design person can also do a design for you that you can follow step by step at your pace. You can ask about prices. Some charge by the job ..some by the hour.
