If your department requires adherence to the APA style guide, there is a quick primer on the verb tense to use in each section of your paper here.
Essentially, most sections should be written in past tense, because when the dissertation is complete and published the research described will no longer be a future event.
For a quick rundown on verb tenses, there is a useful breakdown on this Purdue Online Writing Lab page. It’s always good to have the basics laid out clearly for easy reference, so you can focus on the deeper issues you’re researching.
You’re almost there 