I'm single as well. It's not an issue in and of itself, though it affects things like work and support
Support is a necessity, in terms of you having people (not necessarily family) you can talk to and who give you emotional support. Our emotional supports don't need to be living close to us, although even any one person who can come and have a coffee and a chat with you and give you a hug is helpful. Practically, not everyone does have people who can just pop in and run errands for them. But if there's anyone who can pop round occasionally, that's great. You need to know who can come down if there's an emergency. Child centred support networks tend to grow after adoption, as you meet people with children of similar ages.
Adoptive parents need to take (generally) between 6 months- a year off work (on adoption leave), then most single adopters are back at work either part time or full time (depending on their childs needs)
In terms of where you live, every child needs their own room, and the house/flat needs to be safe and healthy to live in. If you're renting, it needs to be a longer term prospect, so you aren't moving a child in, then moving again in a few months.
I know you may not be seriously interested in adoption, and there actually might be big issues. I'm not trying to convince people or anything. I usually ask because sometimes people have misconceptions about what is and isn't a barrier, so it's just checking that no one's ruling themselves out needlessly!
If anyone is interested in age stats, the Office for National Statistics publish adoption orders by age group, stats go back to the latter half of the 90's. Just remember that it's age at finalisation, not age on placement (some media always seem to misunderstand when they report their 'ONLY 60 babies were adopted last year' blah nonsense)