trying to learn C so i wrote a linked list

linked-list.c

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

typedef struct ListItem {
    int value;
    struct ListItem *next;
    struct ListItem *prev;
} listitem_t;

typedef struct List {
    listitem_t *first;
    listitem_t *last;
    int length;
} list_t;

list_t *create_list()
{
    list_t *list = malloc(sizeof(list_t));
    list->length = 0;
    return list;
}

void push_list(list_t *list, int i)
{
    listitem_t *item = malloc(sizeof(listitem_t));
    item->value = i;

    if (list->first == NULL) {
        list->first = item;
        list->last = item;
        list->length = 1;
    } else {
        list->last->next = item;
        item->prev = list->last;
        list->last = item;
        list->length++;
    }
}

listitem_t pop_list(list_t *list)
{
    listitem_t *item = list->last;
    listitem_t *prev_item = item->prev;

    list->last = prev_item;
    prev_item->next = NULL;
    list->length--;

    item->prev = NULL;

    return *item;
}

listitem_t *get_listitem(list_t *list, int idx)
{
    listitem_t *item = list->first;

    for (int i = 0; i < list->length; i++) {
        if (i == idx) {
            return item;
        }

        item = item->next;
    }
}

void delete_listitem(list_t *list, int idx)
{
    listitem_t *item = get_listitem(list, idx);
    listitem_t *next = item->next;
    listitem_t *prev = item->prev;

    if (next != NULL) {
        prev->next = next;
        next->prev = prev;
    } else {
        prev->next = NULL;
    }

    free(item);

    list->length--;
}

void insert_listitem(list_t *list, int idx, int i)
{
    listitem_t *item = get_listitem(list, idx);
    listitem_t *prev = item->prev;

    listitem_t *new = malloc(sizeof(listitem_t));
    new->value = i;
    new->next = item;

    item->prev = new;

    if (prev != NULL) {
        prev->next = new;
        new->prev = prev;
    } else {
        list->first = new;
    }

    list->length++;
}

void free_list(list_t *list)
{
    listitem_t *current = list->first;
    listitem_t *next;

    do {
        next = current->next;
        free(current);
        current = next;
    } while (current != NULL);

    free(list);
}

void print_list(list_t *list)
{
    listitem_t *item = list->first;
    int randint;

    printf("list length is %d, items are: %d", list->length, item->value);

    while ((item = item->next) != NULL) {
        printf(", %d", item->value);
    }

    printf("\nrandom items: ");

    for (int i = 0; i < 5; i++) {
        randint = rand() % list->length;
        item = get_listitem(list, randint);
        printf("%d -> %d, ", randint, item->value);
    }

    printf("\n");
}

int main()
{
    list_t *my_list = create_list();

    srand(time(NULL));

    for (int i = 0; i < 10; i++) {
        push_list(my_list, rand() % 50);
    }

    print_list(my_list);

    pop_list(my_list);
    print_list(my_list);

    delete_listitem(my_list, 2);
    print_list(my_list);

    insert_listitem(my_list, 3, 9999);
    print_list(my_list);

    free_list(my_list);

    return 0;
}