How Can I Improve My Understanding of Linked Lists in Programming?

I've been getting by with programming until I hit a wall trying to create a linked list manually. It's been really frustrating, and I'm starting to wonder if it's actually simpler than I'm making it out to be. I feel like I don't have the typical 'programmer's brain'—is there anyone who can break this down for me? Here's a snippet of the code I've been working with:

```java
class Vehicle {
String name;
public Vehicle(String name) {
this.name = name;
}
}

class Node {
Vehicle data;
Node next;
public Node(Vehicle data) {
this.data = data;
this.next = null;
}
}

public class PractiseLinkedlist {
Node head;

public void add(Vehicle V) {
Node newNode = new Node(V);
if (head == null) {
head = newNode;
} else {
Node current = head;
while (current.next != null) {
current = current.next;
}
current.next = newNode;
}
}

public void printList() {
Node current = head;
while (current != null) {
System.out.println(current.data.name);
current = current.next;
}
}

public static void main(String[] args) {
PractiseLinkedlist list = new PractiseLinkedlist();
list.add(new Vehicle("Toyota"));
list.add(new Vehicle("Audi"));
list.add(new Vehicle("Yamaha"));
list.printList();
}
}
```