A good programmer will be able to create an feature to meet your needs.
The part you may need to start working on before getting a programmer involved is defining your needs.
To that, I'd suggest doing two things;
1.
Creating some Mockups to show the programmer what you want the feature to look like. Saying you want it similar to X, Y, and Z is a step in the right direction -- but if you want a feature to call your own either you or your developer will have to do some mockups to get a sense of what goes where and what the final feature should look like.
Even a rough design, a sketch you do on some computer paper and take a cellphone picture of (NOT THAT I DO THIS*coughcoughcough*) can give people who are working on it a sense of what goes where.
2.
Making a list of features for your feature. In a customization feature your models are usually broken down into pieces and you have to design ahead of time (or have a massive headache later) which pieces are going to be customizable.
Something like this:
- Hair
- Left / Right Ear
- Eyes
- Face
- Lips
- Eyeshadow
- Neck
- Left / Right Arm
- Left / Right Hand
- Bottoms
- Tops
- Shoes
- Socks
- Back
- Accessory
- Garland
- Trinket
- Background
Then it might go a bit beyond that.
- Do you want users to have a closet to store their clothing? How should this area look and operate?
- Do you want your users to save outfits? How many outfits?
- Do you want users to rate user outfits or to be able to share them on site/social media?
- Is clothing going to be free, purchased with real money, or both?
You also seem to be an artist, so I'm guessing you're going to
make the Avatar bases and some concepts for the clothing? If not, you're going to have to find someone who can. Fortunately, there are many artists around here who can do avatar bases.
Would anyone do work for free? Where can I find someone who might?
Sure;
you can. ?
Knowing how to code is such a marketable skill to have that I recommend anyone who can learn it.
Even if you decide to commission out the work for your avatar feature having a general idea of how it will work will be helpful to both parties since you will be better able to explain what you are looking for, and may be able to fix or adjust some things yourself once you have the final product.
If you are an absolute beginner with coding I have two recommendations on where to learn:
An oldie but goodie -
LissaExplains
This is one of the sites I learned the basics of building a website from Back in the Day (TM). Some of the lessons are outdated, but the fundamentals about HTML, CSS, DIVs and how to include JavaScript are not.
For a more modern place try
W3Schools
You can learn more about Modern JavaScript (Frameworks like React, Angular, and JQuery) and Server Side Languages like PHP and MySQL from here.
From there, you'll need some server space to test and eventually host your product for the public to try.
For that, I and I'm sure some others out there would recommend
DigitalOcean.
If the Command Line is troublesome you can one-click setup Cpanel for a visual guide around your server.
It's around $5 a month ($60 a year) which is on-par with the average price of a hosting service these days. You'll just have to bring a domain name (you don't need one now!) when you're ready to show your site to the public.