I have a W2, and I work 1/3 of the time with my computer (documenting, charting and meeting with other employees) from my home. Can I claim a home office deduction?

Sorry---W-2 employees cannot deduct job-related expenses on a federal return.  Job-related expenses were eliminated as a federal deduction for W-2 employees by the tax laws that changed for 2018 and beyond.  Your state tax laws might be different in AL, AR, CA, HI, MN, NY or PA.

If you live in a state that lets you deduct job-related expenses, the information will flow from your federal return  to the state return, so enter it in Federal>Deductions and Credits>Employment Expenses>Job-Related Expenses

No, If you are a W-2 employee and you don't have an independent business it is considered a convenience that your employer offers you.