Taking hikes is a good way to improve many aspects of fitness. Hiking will improve strength in ones legs as well as improving ones cardiovascular system. Hiking can also have the added benefit of being a good stress reliever. Also one can adjust the difficulty by adding or removing weight in a backpack.
Be realistic with your goals and realize that they don't have to weight related. Make a goal to work two times a week, or to make it to a class once a week. Small goals are much easier to achieve than big ones and they will keep you motivated as you get used to your new routines.