I made this for 
which I organised with: 
Click the GIF to play it, you can also download the PDF of everyone's art for free!!! :-)
While you're here I'll give you some passwords... Wings, Dog, Lisa, Trans, Gay, Bunny, Sparkle
Truthfully I feel bad giving any kind of tutorial on this because I'm sure I did it in a really stupid way that would make any coder cringe... but hey it worked, didn't it???
The original plan was to make a paper doll! This was my workaround when there wasn't enough room on an A4 piece of paper to fit everything I wanted :-)
I made it in Scratch which is a node/module coding website aimed at babys. It's very limited (fixed 480×360 dimensions) and clearly not meant for large projects, but it is quite noob friendly. Then I used Sheeptester's Project HTMLifyer to convert it to a .html file that we could host on our site! Yes this whole process makes it a giant pain in the ass whenever I want to update 1 little thing.
The actual art assets were more simple, I drew a naked base then drew clothes over it on different layers and exported as pngs with transprency.
The clothes are set to move into a certain position if they are touching the base, and into another position if they aren't touching the base. The pages were done by assigning variables to the buttons at the bottom. When you click a page icon, it sets that page's value to "1" and all other pages to "0". Each clothing itedm is set to be hidden and only show when the page I want it on has a value of "1". This is confusing to explain with words, truthfully it's best to just get in there and experiment to find a solution that works for you as it depends on how you want your game to be!
If you are really new to coding you can also "remix" people's projects on Scratch, which is just copy pasting their code into a new project to edit it. It would work as a good starting off point, or a way to see different ways people achieved something.
Here's a screenshot of what the project looks like:
Did I do this in a dumb way? Undoubtably. However I think it is a testament to my stubborness, adapting to the technology you have is good, and I think it's just proof anyone can make a game if you have enough patience!
I'm really dumb, so if I can do it, so can you! Now go make a dress up game. Doctor's orders.
Artwork