How to find a path between two vertices (and shortest path) in an undirected unweighted graph

Question

I want to find a path between two vertices in my graph and look for the shortest. My graph is unweighted and undirected. I use BufferedReader to load the social network graph given in a text file. I already check and there is no edge between the two nodes. I implement BFS to see if the graph is connected and it's not. Do I need to implement DFS to do this? What is the most suitable algorithm to do it?

public class UndirectedGraphs {
HashMap<String, LinkedList<String>> socialNetworkAdj;

public UndirectedGraphs() {
    socialNetworkAdj = new HashMap<String, LinkedList<String>>();


}
public void addVertex(String label){
    socialNetworkAdj.put(label, new LinkedList<String>());
}

public LinkedList<String> getEdges(String label) {
    return socialNetworkAdj.get(label);
}

public void addEdges(String ver1, String ver2) {
    if (!socialNetworkAdj.containsKey(ver1)) {
        addVertex(ver1);
    }

    if (!socialNetworkAdj.containsKey(ver2)) {
        addVertex(ver2);
    }
    socialNetworkAdj.get(ver1).add(ver2);
    socialNetworkAdj.get(ver2).add(ver1);
    //System.out.println(socialNetworkAdj);

}
public int getVertexCount(){

    return socialNetworkAdj.keySet().size();
}



    List<String> bFS (String root){
        List<String> visited = new ArrayList<>();

        Queue<String> queue = new LinkedList<>();

        queue.add(root);
        visited.add(root);

        while (!queue.isEmpty()) {
            String vertex = queue.poll();

            for (String v : this.getEdges(vertex)) {
                if (!visited.contains(v)) {
                    visited.add(v);
                    queue.add(v);
                }
            }
        }
        return visited;
    }
public boolean isConnected() {
    String anyVertex = (String) socialNetworkAdj.keySet().toArray()[0];
    int reachableVertices = bFS(anyVertex).size();

    System.out.println("\nReachable Nodes: " + reachableVertices + " vs. vertex count: " + getVertexCount());

    if (reachableVertices == getVertexCount()) {
        return (true);
    } else {
        return false;
    }
    }

}