It is great that you are willing to keep an open mind and accept a job that you maybe feel you can eventually surpass and do better. You can always work your way up in retail jobs, or restaurants. You just need something to get you off the ground. What about cleaning? Nobody to give you grief, but then you might benefit from social interaction.
I must admit I was always reluctant to do voluntary work because I am from a working class family and I have never had the luxury to work without getting an income.
You could consider a short course at college - hospitality or something