Your grant proposal assignment will require you to
This guide will help you with the resources you need to be successful with this project.
Remember that the research process is just that: a process. A good researcher isn't someone that puts the right words in the search box the first time, it's someone who uses each search to improve the next one. By being aware that you'll circle back and perform tasks more than once, use more than one tool, and look at more resources than you actually use, you'll be better equipped to plan how long your research takes and pick the best sources.
Check out these sample NIH grant proposals to start getting a sense of what your grant proposal might look like:
NIH NAID R03 Successful proposals
The below examples from the journal BMC Musculoskeletal Disorders aren't grant proposals but are 'study protocols' which describe the creation and design of a study...similar to how you will need to propose the design of a research study for your grant proposal:
Search for other examples of successful grants in these awarded grants databases: