Is there a way to shove a part inside a player so that i detect when it touches someone???

I'm not really an expert but you could use a morph system which when a new player joins it automatically morphs them so they have a part in their chest which is invisible like a hit box or just write a script so if a humanoid is detected touching a part with another humanoid it does what you want it to do

UPDATE:

This script should work to morph it onto the player

If you put a script with the code I provided below in serverscriptservice with the part you want inside in the script it should weld it to the players uppertorso if using R15. If using R6 just simply change the UpperTorso text to the part you want

local charAdded = function(char)
    local a = script:WaitForChild('hitbox'):Clone() -- Hitbox should be changed to whatever the part name is
    local w = Instance.new('Motor6D')
    w.Part0 = char:WaitForChild('UpperTorso') -- Change this to whatever part of the character you wish to weld it to
    w.Part1 = a
    w.Parent = char['UpperTorso'] -- This should be the same part as above
    a.Parent = char
end

game:GetService('Players').PlayerAdded:Connect(function(plr)
    if plr.Character then
        charAdded(plr.Character)
    end

    plr.CharacterAdded:Connect(charAdded)
end)

Yo Mast3r,

I would just use Weld Constraints to Weld the parts onto the character's body parts... That way you can have a bunch of hit boxes on different parts of the body part or even one part... For example, if you want a part to be welded to the UpperTorso and have a hitbox on there:

Server Script in ServerScriptService: Weld Part To Torso

local part; -- Initialize this to where ever the part is, it can be anywhere as long as it's not on the client (For FE Enabled reasons)
local players = game:GetService("Players");

players.PlayerAdded:Connect(function(plr)
    local char = plr.Character or plr.CharacterAdded:Wait();
    local u_torso = char:WaitForChild("UpperTorso");
    local new_weld = Instance.new("Weld Constraint");
    local new_part = part:Clone();
    new_part.Parent = u_torso;
    new_part.CFrame = u_torso.CFrame;
    new_weld.Parent = new_part;
    new_weld.Part0 = u_torso;
    new_weld.Part1 = new_part;
end)

That would weld the part to the character's upper torso and then you can detect collision with that part. Remember that my script places the part in the UpperTorso, so normal character detection won't work because the parent of the part isn't the character but instead the UpperTorso... You can change the parent if you want, this was just an illustration of WeldConstraints.

Hope I helped and have a wonderful day/night.

Thanks,

Best regards,

Idealist Developers