Hi, this is my first time here so please be gentle with me!

Ive recently started gardening. I have a very small garden and would like to make the most of the space with evergreens (perennials?), a bit of colour and some veg/herbs. I bought a great book recently which showed tips on how to best utilise small space for veg/plants/flowers.

On one side of the garden is a a white wall measuring 4 x 4 metres. I dont like this white wall and Im thinking of putting up some trellis and having some climbers or something that will be green all year round and flower in the summer. However (and this is why I havnt got into gardening before) Im impatient and want something fast growing so that within the year that wall is covered in foliage. Does such a thing exist and is this achievable? Shoudl I buy a plant that is already well matured? What should I look for when buying trellis or is it all teh same? In my little front garden I have a nice honeysuckle climbing wall, but that goes dormant in the winter. I want foliage all year round.

Thanks
PS
the wall is south facing, but the garden is cold because its exposed and gets battered by the elements.