What would be a good 24" level for doing small around the home projects?
Any preference as to aluminum or polycast plastic? Thanks in advance for
any
suggestions.

My first and most useful level was a 24". Later a 12" or less, most recently
a 48". Aluminum is generally better, and can be used more conveniently as a
straight-edge to mark your work, altho Aluminum can leave marks on
walls.Don't try to save money. I got a top of the line Craftsman 40 yrs ago
and it works fine today. Once you decide on a model, take all the stock off
the shelf, find a place that measures level, then pile 4 or 5 levels on top
of that one to check agreement for both vertical and horizontal. There is
often at least one that tells its own story, has probably been slammed, and
should be rejected.