Is a hint needed here???
I thought it could be ENCHILADA DISH, but I couldn’t assemble the pieces.
Start with the n- only, not the en-.
Anagram
NUTRITION BARS
You can store your weapons here supposedly, underside and all. (7)
ARSENAL (double definition)
The most ratable of Canadian provinces (7)
The most ratable of Canadian provinces (7)
ALBERTA (ratable*)
+++++
All ages are allowed to enter mediterranean avant-garde electronic music group. (9, 5)
How about:
All ages are allowed to become part of avant-garde Mediterranean /German electronic music group. (9, 5)
Tangerine Dream (anagram of Mediterranean + G).
++++
A lady in a mag can scramble the brain’s emotive center. (7)
Not 8 letters?
8 indeed.
AMYGDALA (a mag lady*)
+++++
Ranked forty-ninth among Guatamala skateboarding members. (6)
I don’t know, but my wife does - ALASKA (hidden word).
+++++
Following supper, sounds like you have ground beef - sweet! (5, 6, 5)
After dinner 
s
If your answer is “after dinner cakes”, that’s not quite right - because “cakes” doesn’t sound like ground beef.
How about After Dinner
That, I can accept 
. Your turn.
Off After Dinner Mints:
Ninja goes after head of state and puts him to sleep (7)
When I made that puzzle I thought ninjas were exclusively male. I’ve since learned there were female ninjas. So how about:
Lee Harvey Oswald goes after head of state and puts him to sleep (7)
Is it SANDMAN?