I'm trying to think of what a typical town centre in the UK would be like so I can describe it. There are many different types so there isn't really a 'typical' town, but this is pretty accurate for many of them.
I'm going to use the town of Woking in Surrey as an example, because I know it well. It's an average sized town by UK standards and has a population of about 65,000. It's a commuter town serving London (about 30 miles south west of the capital) and has a large railway station. The town centre consists of two or three fairly large shopping streets and two undercover shopping centres, what you guys would call 'malls'.
Most of the chain stores - clothes shops, homewares shops, shoe shops, mobile phone stores, department stores etc, are located in the malls. There are two malls: Peacocks and Wolesey Place. Between them they house around 150 shops. Here's a list of what you'll find in there:http://www.shoppingwoking.co.uk/shopping/
The larger one also contains a cinema and there's a theatre just off to the side of it too. There's a large car park on top of the bigger centre which has approximately 2000 spaces.
There are more shops on the outside shopping streets. There you'll find things like banks, estate agents, temp agencies, hairdressers, charity shops, cafes, market stalls, restuarants and pubs, basically anything that isn't a large chain.
In addition to all this, there are office buildings and other places of business where people would go to work.
All of this is concentrated into a fairly small area. Here's an arial shot of Woking to give you an idea of its size/layout: http://goo.gl/maps/x3I0o
You can see the town centre concentrated in the middle with the outlying residential areas around it.
Each of these main housing areas is on a bus route, so you can get a bus into town in about five or ten minutes. Buses are usually about ten minutes apart and the return fare into town is about £2.50 (although i've not been there in a few years, it may be more now).
There is also a small 'out of town' shopping area, what you guys would call a strip mall, I think, which has a big DIY superstore, a pet superstore, and places like that, and elsewhere on the outskirts of town there are a couple of large supermarkets with their own parking (Morrisons, Sainsbury's and a big Tesco in the next town) where people would go to do their weekly food shop.
So, you really can go 'into town' and do everything you need to do.
The majority of average-to-large sized UK towns are like this. Of course we have other types of towns too. There are very small towns which might have one shopping street (usually a throughfare through the middle of it), and villages, which are very small and predominantly residential and might have a local grocery shop, a pub, a small post office and a church. People who live in places like this would normally drive to the nearest town to take care of whatever they needed to.
Bigger cities like London and Birmingham are a bit different to this and it'd take a separate post to describe those.