Survival Weapons/Tools
Whole sets of books written on this subject.
Everyone has an opinion and hates the opposition.
Your jurisdiction, morality, skillet, and environment will dictate the best and or adequate choices.
Minimum tools you will need:
Mid size knife
Hatchet or machete
Quality multi-tool like Leatherman
Small prybar
Accurate watch
Small compass with map
Pencil and notepad
If you need a weapon: (yes, you do)
A strong hiking staff about your height is a must.
This is a walking aid, and a weapon.
A small slingshot with spare bands and ammo is legal almost everywhere.
A large knife that can double as a spear. The Cold Steel Bushman is a great practical knife to fill this roll.
Firearms
I prefer a .22 LR target pistol as the go to firearm for survival. The ammunition is small and light, allowing the easy carry of hundreds of rounds. Very effective beyond its size. Carrying a larger caliber pistol is very good as a main defensive weapon. I prefer the 1911 in .45acp and as many extra magazines as practical. When law breaks down and you must travel, defensive firearms can be a life saver.
Few firearms can beat the AR15 for light weight and capacity. Ammo is relatively light. Easy enough to find in the SHTF situation. Shotguns are versatile but the ammo is very heavy in comparison. Best for defending the home.