Whats the age you have to be to carry a knife in stores and in public?
A short summary: (Just my opinion based on what I have read and from 50 years carrying knives....)
You have no rights until you are 18 other than what your parents grant you. In your picture you look too young to be out and about with a knife, other than a small pocketknife, without adult supervision.
You can not carry a concealed weapon without CCW permit. (age 21.)
A weapon is anything intended to be a weapon or appears to be intended for such. If the design of knife looks like it is used only as a weapon, you better show you use it to cut boxes at work with it. If you don't get in trouble for anything else, not likely to get in trouble for a knife but, if you do get into trouble and have a knife=MORE trouble.
Fed law allows anyone to carry a knife concealed, if blade is 2" or less.
Wis. has no length limit except in cities of Bayside, Racine, Sheboygan, Wauwatosa, Millwaukee Co. where knives of <3" can be carried without permit. So, most of the state you can have a knife any length and carry it openly or in a pocket, under your jacket etc. As long as that knife is intended to be used as a "tool". If in design or intent is to use it for a weapon you will likely get in trouble. Is up to the police or judge to determine. (A big grey area.) The police do not have to make that determination unless someone complains. So, you can carry a knife in your pocket or in the open depending on the location or situation and what your reason for having it is. During hunting seasons we see people all over with camo, orange, and big knives on thier belts. Even see kids as young as 10 with hunting knives on them. Fishermen carry long fillet knives. Most of us go into stores, cafes, gas stations, etc. without a second thought and no one pays attention. It is just a tool for the activity we are doing. If you have it on you for protection or defense then it is a weapon. A screwdriver or a hammer, even a sharp stick can be a weapon in the same way. All depends on your attitude, appearance, perception of those around you.
If you have a screwdriver in your back pocket because you were working on your car and walk into a convienience store, nobody is going to care. Slip that same screwdriver into the front of your saggiebaggies or up your sleeve and approach the cashier? that will likely be considered threatening. A hammer in your carpenter pants loop=no problem, grip it in your fist and look mean=problem. Appearance and projected attitude is what will make the difference on whether the knife is going to be considered a tool or a weapon. If ever quetioned about it? you "just carry it for whittling, gutting game, dig splinters out of my fingers, scrape mud off my shoes, duh, never thought of stabbin anyone". Get by with a lot more if wearing flannel and jeans that fit also. Easy on the tats and jewlery. Attract extra attention to yourself and the knife stands out. Redneck with a knife is common, punk with his butt hanging out and knife??? likely get ya called in.
If I have a 7" bowie in a sheath on my hunting pants=no big deal. If someone asks what I got the big toadstabber for? "just gutting deer". Same knife peeking out from under my jacket in a shoulder rig=WEAPON! Many of us carry folders and multi-tools with knife blades in belt sheaths all the time, nobody says a word. Tell anyone you got it for self defense, it's a weapon not a tool.
A 5" fixed blade? Just to "carry around"? What do you need it for? What use do you have for it? Not a good idea unless you are going to and from the woods. Leave it home or in vehicle when entering stores and other public places. Why not a 3" folder in pocket or belt pouch? I don't wear a belt to hold up my pants, I wear a belt to hold my knife. Often have multiple knives and tools in pockets to where I need suspenders also, hahahahahah....