Single-Linked List in C - beginner

I'm a python dev by day trying to learn C.

This is a simple implementation of a singly linked list. As a noob I would like comments on style and C conventions as well as functional remarks on memory management etc.

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

/*
        --------linkedList---------
        |                          |
        |                          |
        |                          |
        |                          | 
        *head  -->  nodes  -->   *end   
*/

struct linkedList {
    struct node * head;
    struct node * end;
    int len;
};
struct node {
    int id;
    int val;
    struct node * next;
};
struct linkedList * createList() {
    struct linkedList * l_list = (struct linkedList * ) malloc(sizeof(struct linkedList));

    l_list->head = NULL;
    l_list->end = NULL;
    l_list->len = 0;
    printf("created list\n");
    return l_list;
}

struct node * createNode(int id, int val) {
    struct node * n_node = (struct node * ) malloc(sizeof(struct node));

    n_node->id = id;
    n_node->val = val;
    n_node->next = NULL;
    printf("created node\n");
    return n_node;
}

void addNode(struct linkedList * ptr, int id, int val) {
    struct node * new_node = createNode(id, val);
    if (ptr->len == 0) {
        ptr->head = new_node;
        ptr->end = new_node;
        ptr->len += 1;
        printf("created a list and added a new value\n");
    } else {
        // update next of previous end
        // make new end this node 
        struct node * temp;
        temp = ptr->end;
        temp->next = new_node;
        ptr->end = new_node;
        ptr->len += 1;
        // printf("updated a preexisting list\n");
    }
}

void printListWithFor(struct linkedList * someList) {
    struct node currentNode = * someList->head;
    printf("current length of list is %d\n", someList->len);
    printf("first item is %d, last item is %d\n", someList->head->val, someList->end->val);
    if (currentNode.next == NULL) {
        printf("current node id is %d, with a value of %d\n", currentNode.id, currentNode.val);
    }
    for (int i = 0; i < ( * someList).len; i++) {
        printf("current node id is %d, with a value of %d\n", currentNode.id, currentNode.val);
        currentNode = * currentNode.next;
    }
}

void printListWithWhile(struct linkedList * someList) {
    struct node currentNode = * someList->head;
    struct node endNode = * someList->end;
    printf("current length of list is %d\n", someList->len);
    printf("first item is %d, last item is %d\n", someList->head->val, someList->end->val);
    if (currentNode.next == NULL) {
        printf("current node id is %d, with a value of %d\n", currentNode.id, currentNode.val);
    }
    while (currentNode.id != endNode.id) {
        printf("current node id is %d, with a value of %d\n", currentNode.id, currentNode.val);
        currentNode = * currentNode.next;
    }
    printf("current node id is %d, with a value of %d\n", currentNode.id, currentNode.val);
}
struct node * findNode(struct linkedList * someList, int id) {
    struct node headNode = * someList->head;
    struct node endNode = * someList->end;
    struct node * nullNode = createNode(-1, -1);

    if (headNode.id == id) {
        free(nullNode);
        return someList->head;
    }
    if (endNode.id == id) {
        free(nullNode);
        return someList->end;
    }
    struct node * currentNode = headNode.next;
    while (currentNode-> id != endNode.id) {
        if (currentNode->id == id) {
            free(nullNode);
            return currentNode;
        }
        currentNode = currentNode->next;
    }
    return nullNode;
}

int delNode(struct linkedList * someList, int id) {
    struct node * headNode = someList->head;
    struct node * endNode = someList->end;

    if (headNode->id == id) {
        // remove node, replace it with next node, free memory
        struct node * temp = headNode->next;
        someList->head = temp;
        printf("removed a node with id of %d and value of %d\n", headNode->id, headNode->val);
        free(headNode);
        someList->len -= 1;
        return 0;
    }
    if (endNode->id == id) {
        printf("removed a node with id of %d and value of %d\n", endNode->id, endNode->val);
        free(endNode);
        someList->len -= 1;
        return 0;
    }
    struct node * currentNode = headNode->next;
    struct node * prevNode = headNode;
    while (prevNode->id != endNode->id) {
        if (currentNode->id == id) {
            struct node * temp = currentNode->next;
            prevNode->next = temp;
            printf("removed a node with id %d and value of %d\n", currentNode->id, currentNode->val);
            free(currentNode);
            someList->len -= 1;
            return 0;
        }
        prevNode = currentNode;
        currentNode = currentNode->next;
    }
    return -1;

}
int main() {

    struct linkedList * list = createList();
    addNode(list, 1, 7);
    addNode(list, 2, 6);
    addNode(list, 3, 11);
    addNode(list, 5, 92);
    addNode(list, 18, 6);
    addNode(list, 10, 3);
    addNode(list, 50, 9);

    // printListWithWhile(list);
    // printListWithFor(list);
    printf("\n");
    struct node * foundNode = findNode(list, 1);
    printf("Node id : %d\n", foundNode->id);
    printf("Node val : %d\n", foundNode->val);

    printf("\n");
    // printListWithWhile(list);
    delNode(list, 2);
    printListWithWhile(list);
    delNode(list, 18);
    printf("\n");
    printListWithWhile(list);
    return 0;
}