How do I actually start?

[Likeaburstcouch]

We recently bought our first house and have a small garden, maybe 7x7m, but about 2x7m is terrace.
It's currently just a lawn. If I want some shrubs for colour and to hide a bit of fence, do I go and buy a shrub and just dig a hole? How much would a big shrub cost?! Is there a chance it would die over winter?

I know this makes me seem like I've never heard of Google. I'm not ignorant- I've read and watched Monty Don and dreamed of making him proud. I've drawn a plan of the garden. I am just overwhelmed.

The soil is clay... I think?

@Likeaburstcouch The PH is only important if you want to grow things like rhododendrons, heathers and other things that like acid soil. They don't grow well at all in alkaline soil.

Easiest way to tell: if you live in a hard water area and get limescale in your kettle, then it is more than likely you have alkaline soil.

Excellent idea, the neighbour likely has similar soil and obviously the same climate.