I left my full time job at 57, which meant I had over 8 years to go before my state pension kicks in next year. My (small) occupational pension started at 60.
I do a few hours of consultancy work for half the year, which boosts my income a bit, but more importantly makes me feel that I’m still relevant and that I contribute to society. The plan was to do it until my state pension, but I may well decide to carry on beyond that if my employer still wants me. I’m lucky in that there are no fixed hours and I can do most of it from home though. I don’t know if I’d want to be setting the alarm and commuting in bad weather- I had enough of that before I left my old job.
My local garden centre seems to be staffed entirely by students and the retired, so I don’t think you’ll have problems finding work if yours is the same. It’s flexibility they need though, so you may not get regular hours. Bookshops are less accommodating I think. Waterstones used to want a degree in a relevant subject, or for staff to be students in the area they were covering, so it’s more difficult to get in unless you are lucky with which department has a vacancy. A private local store might be different, of course, but they are thinner on the ground. I always thought I’d like to work in a wool shop as I love knitting, but I now think that doing it all day might kill my pleasure in it, so it might be worth considering that, too.