My garden is in a poor state, when we moved here it was very overgrown, nettles and weeds everywhere and the grass was 5 foot tall (i'm not kidding) well, we managed to clear the garden, but it looks awful, there is rubbish that we are taking to the tip tomorrow, my shed has seen better days, there is weeds and nettles back again, and the grass looks terrible, I want somewhere nice for the kids to play and for us to sit outside in the evenings, I don't have a lot of time because of the kids disablities, and can't afford a gardener to help me clear it, I would need safety rubber tiles for the kids swing set to go on, and BH, its all too much to even think about, all we do is cut the grass and cut down the nettles, and I want a lovely garden..
the end of youyr garden qwhere your shed is, demolish the shed, and cut down the nettles etc. patio the area, and also put a new shed there. its a very sunny spot in the evenings, obviously work round the trees or apply to the council to remove/move them.
you can cover fairly big areas with a wild flower meadow mix... which will grown in uneven poor soil.... although level it out a bit and weed it... then you just hack it down after flowering... leaving it to self seed for the following year. Its a great time to sow all kinds of seeds directly into the ground. If its a sun trap try something like pumkins... they cover huge areas and are easy from seed, same with marrows, courgettes. Runner beans are quick too.... just need a few beanpoles. Also if you have a local college that has horticulture courses, they may be worth a call as students may be looking for work expereince or a project.
It crashed for me online, but is ok now I've downloaded it.
Failing that, draw up a plan for the whole garden, then do a third of it at a time. Do, say, patio and containers this year, lawn next year, flowerbeds year after or vice versa. That way the whole thing will look integrated when you've finished.
You could make a patio by using weed-proof membrane (on level ground) with gravel on top - unless you've got cats or kids like mine who will willingly redistribute the gravel all over the garden!
I did try the gravel thing before to stop the weeds, put down membrane and brought bags of gravel and my kids keep pouring it into buckets and tipping it on the grass..... took my all of last summer to clear it again... grrrr
Paint the shed a colour with some wood paint, stick a piece of trellis up the side then grow a climber up it. I tried this with a really grotty one where we used to live thinking it would still look pretty bad, but it came up really well. The people who live there now use it as a child's playhouse. Bark chippings is a cheaper solution for under play stuff if you don't want grass, but be warned our cat used ours as a litter tray so we had to move the stuff back onto the grass.
Once you've decided what to do, have you got some helpful friends you could ask to come and help for a day ? You could get a BBQ going and feed them for their efforts.