Recently I started investing in some items to start my own home studio, which I am young so I do not have a bunch of money to spend and don't get any help paying for my own belongings, just making this clear now. I am very satisfied and happy with what I have managed to get at this point.I have an Electro-Voice Co9 Colbalt Premium Vocal Mix (Dynamic) microphone,Standard 3-Pin Type (5 feet long) microphone cables, Musician's Gear Tripod With Fixed Boom, for headphones I went with the Audio-Technica ATH M40x Full Sized Professional Monitor Headphones, my choice of audio interface i had to go with the Focusrite Scarlett 2i4, which actually came with a free professional DAW program software called Ableton Live 9 Lite, and last but most certainly not least, the laptop that is holding everything together is a HP Pavilion g6!So I finally got everything hooked up and working properly (I believe), and I came across an issue. When ever audio is played into my M4O's (through the headphone output of the interface) it is very quiet.
My question is this: Would the solution be just to get a headphone preamp? If so could I get a recommendation as to which kind?
If so I will make sure to do that, which also brings me to another question, which is:
Besides the preamp (if recommended to do so), what item(s) should i look into purchasing next?

Thank you for taking time to read my post, I really appreciate it. I would also like to say thank you in advance to anyone who kindly would offer their help to me! Any questions for me? Go ahead and feel free to ask away! Thanks!