Start as Georg says by tidying it up. Then decide what you would like, what you will use it for, how much work you want to do and what the budget is. You could pave or deck the area close to the house and put a table and chairs for outdoor meals and a few pots of flowers. Then you could do a gravelled area for low maintenance and plant some things like lavender, rosemary and thyme in it. Clean and rake the area level, put down weed suppressing permeable fabric under the gravel. Do you need an area for vegetables? Do you need a children's play area? Forest bark is good as a base for that. You could put a rose arch at the end with a comfortable seat and a climbing rose or honeysuckle for the scent. Have a look on internet, garden magazines, buy or borrow a book about garden designs , low maintenence gardens, long thin gardens. You may find that you are enjoying yourself and you don't mind a bit of maintenance after all!