C++ why is there constructor error and why does trying to add to the stats not work?

#include <iostream>
#include <string>
#include <cmath>
#include <stdlib.h>
#include <random>
#include <ctime>

using namespace std;

int iseed = (int)time(0);
srand(iseed);
int d6 = (rand() %6) + 1;
string name;
string race;
int str = d6+d6+6;
int dex = d6+d6+6;
int con = d6+d6+6;
int inte = d6+d6+6;
int wis = d6+d6+6;
int cha = d6+d6+6;
int hp = ((con - 10) / 2)  + d6;
bool simpleWeaponProficiency = false;
bool martialWeaponProficiency = false;
bool exoticWeaponProficiency = false;
bool while_1 = true;

void characterCreation() {
    while (while_1){
        while_1 = false;
        cout << "Your name?: ";
        cin >> name;
        cout << name << ", your sure?" << "\n";
        string nameChoice;
        cin >> nameChoice;
        if (nameChoice == "yes") {
            break;
        } else {
            while_1 = true;
        }
    }
    cout << str << "\n";
    cout << "Alright, " << name << ". where do you hail from?" << "\n";
    cout << "The Human Cities? The Elven Forests perhaps? or the Mighty Dwarven Kingdoms?" << "\n";
    string origin;
    cin >> origin;
    if (origin == "the human cities" or "human cities" or "human") {
        race = "human";
        str + 1;
        dex + 1;
        con + 1;
        inte + 1;
        wis + 1;
        cha + 1;
        cout << race << "?" << "\n";
    }
    cout <<  "Strength:" << str << "\n";
    
}

int main() {
    cout << "Welcome to my adventure game!" << "\n" << "Please type everything in lowercase." << "\n";
    cout << "-----------------------------" << "\n";
    characterCreation();
}

main.cpp:11:6: error: expected constructor, destructor, or type conversion before ‘(’ token
   11 | srand(iseed);
      |      ^
main.cpp: In function ‘void characterCreation()’:
main.cpp:49:13: warning: statement has no effect [-Wunused-value]
   49 |         str + 1;
      |         ~~~~^~~
main.cpp:50:13: warning: statement has no effect [-Wunused-value]
   50 |         dex + 1;
      |         ~~~~^~~
main.cpp:51:13: warning: statement has no effect [-Wunused-value]
   51 |         con + 1;
      |         ~~~~^~~
main.cpp:52:14: warning: statement has no effect [-Wunused-value]
   52 |         inte + 1;
      |         ~~~~~^~~
main.cpp:53:13: warning: statement has no effect [-Wunused-value]
   53 |         wis + 1;
      |         ~~~~^~~
main.cpp:54:13: warning: statement has no effect [-Wunused-value]
   54 |         cha + 1;
      |         ~~~~^~~
make: *** [<builtin>: main.o] Error 1
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