I'm using OShop module to develop my commerce website (which is my school project) Everything is fine but the feature "customers registering" I have no ideas how to do it so far. So has anyone done this before? Please help me out on this. Thanks so much!
You need to recreate a registration form and add the user created to a Role (buyer), this role will have very specific permissions which will allow him/her to navigate your e-commerce features (modules-parts). here is a link to a post explaining how to create a registration form with dynamic forms.
Then look how to create a Profile Part, Addresses, Basket in that site too, although there are other e-commerce modules which should help you understand the scope and how to proceed to fulfil your project's features.
Looking at others code is the best way to learn and Orchard is best for that. check out this project nwazet commerce. there are other projects that create facades to a central system and Orchard just behaves like a 'client' of sorts, but this one its all in the module. Follow the link to the repo, the last update was 6/2015.
Keep in mind the MVC-way and the Orchard-way and try to lean towards the Orchard way. It really makes life easier afterwards. Also will give you deep understanding of the framework.
Good luck