I'm not sure in what you mean by "One by One", but if your question is how you get some result from the first task so you can make a decision in your gateway the answer is to have a process variable (you already have 'loginStatus' variable) and then assign the output of the first task into the process variable. Then, in the flows coming out of your gateway you can write something like: "return loginStatus == true;".
Hope it helps.
Best Regards,