Don't do anything drastic yet lyndy, you don't know what you have in the way of spring flowering shrubs and bulbs. You really need to live in a house for a full year to see what you have in the garden. You could tidy it up by pruning the bushes back and tackling stubborn weeds with Round Up. Good luck, Judy
I agree with judy,take your time,you will never do it all in one go,have a lot of patience and concentrate on one small area at the time,don't flit from one part to another,if you can just tidy a few square yards at the time you will soon notice a difference, good luck, Ray
PS, If you have any large bushes,fruit trees etc, as a general rule of thumb never cut back by more than one third this will keep it healthy.