>>340350by the sound of it you need to do more research man, to be honest. google.
maintain a weight under 35lbs (including the bag)
sawyer squeeze is the cheapest most practical water purifier. Everything else youll find in research. google.
pic related is my kelty red cloud 110. Its not that cheap. $250. however I just got a magellan pinejack for $40. google it. Make sure that it has a frame, such as an aluminum or plastic stay. A lot of people on here have never carried weight more than a few miles and dont know wtf theyre talking about. If it doesnt have a frame, its not for long treks. Google it. Also idk what you mean by "just start walking" But good luck with that. google.
also google