I thought labourers get paid quite a good wage, many of my friends do labouring, ground work and scaffolding and all have more money than me
Obviously you are fit and must enjoy outdoor work (which I miss nowadays being stuck in an office 24/7), how about gardening/landscaping?
You must know how to dig foundations, can you lay patio slabs/decking? Cut hedges, mow lawns etc. Buy a decent van, whacker plate, lawnmower and tools, price yourself cheap to start off and to get a customer base.
Check out my sig for a cheap cost effective way of advertising your services, knock on doors in the evening and hand them to potential customers face to face.
The market is absolutely saturated with website designers, it's not impossible but will be an up hill battle which will involve lots of training if you have no experience.