This was extracted from your photo. The job was usual background removal (=make all unwanted parts transparent) . Next the image was vectorized (=traced to Illustrator style format) with limited color palette and some smoothing. A black outline and a shadow was added.
Used software and some details:
Background was removed in Photoshop. GIMP (freeware) would go as well.
The image was copied and pasted to Inkscape (freeware) for vectorizing. Its Path trace was used. Tracing settings: 12 colors, stack scans, no background, smooth.
Many white parts came out as too grey. Those parts got manually white fill. The bottom shape got manually black stroke.
A black copy was made. It was blurred, made partially transparent and moved a little aside. That's the shadow.
Vectorizing in Illustrator (=Live trace) has much more possible settings than Inkscape's path tracing, but this case didn't need them.
The whole job took less than 15 minutes, but a full novice needs at least 2 weeks of properly guided practicing to do the same without step by step guidance.
If you cannot use Photoshop and Illustrator well and haven't at least 2 weeks full time to practice, get a professional.
ADD: The preceding answer can be seen to have something useful, but the question is reshaped to much more definitive. If it happens that you must design new sports uniforms for whole league, the preceding answer is ridiculous in terms how it helps to perform the task - a new masterpiece in the seemingly ever growing family of the monuments of slow-wittedness.
So, if the task is to design new uniforms for use, you HAVE a problem. Designing a league-wide set of uniforms that have something common that represents the league & supporters and still all must be unique, is much more an art project than technical one. It's technical as a project management task and taking into the account the manufacturing process of final clothes.
The project needs professional help. Three different skill sets at least are needed:
- doing business with cloth producers
- sport cloth artistic design taking into the account the manufacturing process
- general management (negotiations with league management supporters and teams)
Someone must as soon as possible make some suggestions to league management about
- who commands who
- who can suggest and what
- sketch of the project plan
Quite soon it's time to select the manufacturer and starting to make actual design data collection obeying the manufacturing process limitations
Cloth manufacturers obviously have some graphic templates "add your artwork". It's surely useful to get them. The designer is needed to make reasonable suggestions on what is selectable, what is fixed and what can be decided in teams.
Proper templates for most common purposes are available also as independent products. You seemingly have got from member @Webster an answer with more details of templates. Read it!
Everything simply isn't technically printable. The uniform appearance of the league, demands from the supporters and the need of unique artistically satisfying clothes surely nail a bunch of limitations.
When the frame is fixed, the teams also should have a possiblity to decide something.
Really, this is much more than cartoonizing a photo. But if the technical side of creating the images of the cloths is interesting, this site has several discussions about it. Here's a couple of simple (only T-shirts) examples:
How can I mockup a custom stripe fabric on a t shirt
Squeeze the neck of a t-shirt