In reply to Zen:
I think you'd be better climbing at Ibrox wall and/or TCA. I don't think many (any) serious climbers climb at X-cape. Seeing/meeting more serious climbers climbing well will help you improve.
Being light is generally a good thing! I doubt it will hold you back. Light weak climber tend to learn good technique quicker than burly strong guys.
Here are some places where people start climbing though you'll need a fair bit of gear and some education if you are to avoid killing yourself...
https://www.scottishclimbs.com/wiki/Auchinstarry_Quarry
https://www.scottishclimbs.com/wiki/Benny_Beg
Dumbarton Rock is good for bouldering but can be a bit intimidating at first.
Check out the Neil Gresham training DVDs and find a good rock climbing technique book for the knots and stuff.
Get a pair of shoes, a harness, belay plate and krab and a chalk bag. It getting a bit late in the year for outdoor rock climbing in Scotland so I would take your time in getting other gear together as you wont use it much before next march.
Good luck