I need some inspiration

wow amazing size,i wouldnt be able to help you but im sure there will be someone along shortly,goodluck

Welcome to GOY.
Here are some things to think about before you go rushing off to buy plants.
What style of garden do you want - cottage garden, prairie planting, modern and sculptural?
How much time do you want to devote to looking after it?
What direction does it face? If it is shade for much of the day, this will influence what plants will grow well
What sort of soil do you have - heavy clay, dry sand or something else? Is it acid (are the neighbours growing things like rhododendrons)? This will also influence what plants will do best in your new garden.

Then just browse this site for ideas, visit gardens and read garden magazines and get some inspiration. Good luck

Is your house a relative new build? I would dig a sample area of about a foot square. Dig down and check out the quality of your soil as Andrew says. Many builders nowadays just dump the spoil on the garden after digging out the foundations and turf over it. This leaves the structure of the soil useless, full of rubbish and nutrient free. People tend to use raised beds to save replacing the whole area with topsoil.

First thing I'd think about is whether you want any grass at the front. This needs cutting, obviously, and not everyone wants to cut grass in their front garden. The only thing you could replace it with, though, is some kind of paving or hard surfacing, and this is expensive.
Then you need to think about what kind of plants you'd like - how high, evergreen or not, what they'll look like in winter as well as summer, how much work they'll be, what kind of effect you want.
If you don't know much, it might be better to stump up for a professional to give you a consultation and a drawing - I end up doing this for people all the time, and they often do the work themselves, if they're able.

I suggest you look through the pages on this website. You will get plenty of ideas from this, and you can always mix and match what you find. But find out what sort of soil you have before you begin, then do a bit at a time. And remember that gardens evolve, If something doesn't look right where you first put it - move it: if it's not happy where you first put it - move it. The garden will let you know when it's ok.