Merchant City isnt too far from the city centre. 5 mins ish walk depending on were you are.
But not the end of the world.
You have the Goma(Gallery of modern art)its free to get into and it right in the centre of glasgow.
You have the shops all around the city centre.Except from my knowledge there isnt a great camera shop about the city centre.
You have the botanical Gardens down the west end.Where byers rd and great western rd cross.
Jump on the subway and it will take you down as parking down there at the weekend/days can be a nightmare and theres is wardens everywhere somedays.
There is lots of small cafes/eateries down here and up great western rd too.
A couple of my favorite(usually go down well on first dates)

You have two fat ladies(its a fish restraunt)Very nice,not the cheapest,and you can basically see you food getting cooked at the front.
Two Fat Ladies - West End Glasgow Restaurant booking reservations
Another one is Rogano's in Royal Exchange Square
And then a few doors down in the square you have Dimaggio's
Its not a michelin star restraunt but the food does taste good.Pizzas,pasta and the deserts are pretty good too.
Shop wise.You have the usual Hmv,foot locker(Anti christ),zavvi
If you into designer you have cruise(personally its only for footballers and arseholes)Its far too pompus for me.
All Saints(Ingram St I get a better vide from here and the staff are pretty nice too) is pretty good too along with Cult on Queen st
Another one is Size its basically a trainer shop but you can get some descent kicks in it.
You have aspecto with is just off gordon st.They do some rare ish adidas trainers.
Then last but not least possible one of my favorite shops in glasgow!
Fat Buddha,Great gear,they do vinyl toys and lots of funky books on a arrange of diffrent stuff.
I will add to this tommorrow night