Help me turn this into a grow room

It's a sliding door wardrobe but looks the perfect spot to start a grow..

What are your dims? You're gonna need intake and exhaust. Anything is possible, people do small grows in PC cases. Go for it!

Dims? Oh! Dimensions
Yeah, what are they? Looks like a sound potential grow closet...

45 inches in length and 20 inches in width does this sound OK?

Here's a quick drawing of how I imagine it

Look like a good start. You're going to want to add more cfl lights as your plants gets bigger
Have you thought about air extraction? No need for a fan for intake and outtake, one intake will do, maybe a pc fan with a grow this size?

Pull the air out at the top and have a passive intake.

I'm only growing one at a time I do have a pc from my old pc but it is only little this is my first ever grow

No problem. No matter what area you use, you will still need to pull the hot air out the top or you'll get too warm. Just moving the air around with a fan inside is not enough.

Plan on making the hole bigger and getting a washing machine hose pipe and run it out the window... Cheap man's air filter

right on. Looks good. probably a 4" dryer hose would work great.

Made a USB fan from an old 360 slim I had

Whats the height? I also grow in little closets but yeah I use the ScrOG method to keep my plants short and to give me enough space to easily manage everything, when things get too tall you get issues with them pressing up against the lights and such, I highly recommend you take a look at the ScrOG method its easy and will help keep things manageable plus it will give you a nice harvest. You might have trouble with the light proofing for flowering because its a sliding door, if I were you Id go out and get some black duct tape and without sticking the door in place try and get the edges so you have no light leaks it'll save you hassle later and also its essential if your trying to be stealthy. Id pinch the duct tape together in the middle so it sticks to itself and makes a kind of ridge that the door can slide over without stopping but still covering the edges.

Oh and a fan is not something you should cheap out on, i would know because thats exactly what I did, remember when your using a small space it takes a lot less energy to heat that space up and if you want to use an HPS/HID I recommend getting a good fan instead of a cheap one because my 250W HPS heated my space up to nearly 42C so about 100F in all of an hour, now I have an extractor fan and cool tube to try an keep temps down and its still a battle the weather isn't even that hot out yet either so I'm a lil worried about what happens when it gets hotter

^^^ Top advice rnint! ^^^

My room is above room temperature a little because I have an immersion boiler outside but can keep the wardrobe cool

also make sure you run it dry with no plants or anything in it for a full light cycle so you get an idea of what the temps are like before you stick your plants in.