Your final assessment will be an all day assessment where you will be given a spec and expected to build it out. You will also be pulled out individually to go over some fundamental javascript.
If you practice your Array Prototype functions you should be fine!
Clone this practice repo: JS-enums
Basically make the tests pass.
There is going to be some Async-Javascript in your final assessment. To solidify some of your Promise chops I'd recommend that you go over the Promise Practice lesson and build out the staff page || Look over some of the first itterations of SWAPI-Box (Don't go and build SWAPI-Box thats a waste of your time. Look over your code and understand it)
Redux is going to be a requirement so you can either continue to build your personal project to get that practice or build another Ideabox. One thing that might be helpful is revisiting the Starting Up Redux to reinforce your understanding of the react-redux lifecycle.
React Router will be optional in your final assessment (you don't have to use it but knowing how to use it might be very useful). With that being said you might want to go over the router lesson that Sir-Limbo created.
You will be expected to test your application. Action, Reducer, Components, and Containers. I would recommend writing test for your personal project because that is real life practice, but if you need some testing practice check out the Unit Testing React lesson, Testing Async, and Testing Redux.
If you are working on your personal project and coding on the side you are more than prepared to slay this final assessment. Ultimately I think you should treat the building of your personal project as your final assessment study guide. You will get so much more out of building something you care about and it will help you solidify the skills needed to pass this module.