I haven't been alone but I nearly have and went on my own with just my 10 year old daughter to Ibiza. I'd certainly consider going alone if it was either that or not going at all and somewhere popular with Brits like the Med or Canaries would be an excellent choice if you weren't that confident IMO. Oh and I've been to Gran Canaria twice. Main downside for me is I love the beach and sea swimming/snorkelling which none of the Canaries are particularly nice for.