One of the first things that sticks out about your homepage where I think you could get a quick win is by organizing your products better so that it's easier for visitors to find what they are looking for. Think of it like going to a clothing store in person: they have a rack for hoodies, maybe a shelf for jeans, a section for boys and girls, etc. Organizing your website should take a similar approach. You can do this by creating more collections specific to the type of product and then adding it as a "featured collection" section in your theme editor:
Also, the clothing industry is very competitive and that's why it's especially important that you think hard about planning your brand and it's identity. Most people are drawn to a brand of clothing because of what it stands for. One of my favorite step-by-step guides on learning about the elements of successful branding can be found here. It's absolutely free to read.
If there is anything else I can help you with, please let me know.