i am pouring a 5m x 5m concerete base inside a course of 7n blocks do i need expansion gaps around the edge

Answer 1

no

Answer 2

If this is an exterior pour (hopefully with mesh or rebar) or poured thicker than about 2 inches indoors: I would put them in... also I would saw-cut some across it in a grid pattern as well and then use self-leveling caulking to fill in the cuts. Concrete likes to be 6'-10' square (max) if it's a sidewalk and you want it to last without cracking where you don't want it to crack. The saw cuts will 'install' weak spots in the pour so that any expansion/contraction will happen where you put them and thus not somewhere you didn't. This will keep it looking nice for a very long time.