Sorry---W-2 employees cannot deduct expenses for working from home. Job-related expenses were eliminated as a deduction for W-2 employees by the tax laws that changed for 2018 and beyond. Your state tax laws might be different.
Yes, start up costs are deductible. You may deduct qualified start-up costs you paid or incurred while setting up your business up to $50,000. It can either be deducted in the year you open the business up to $ 5,000 and amortized the remaining for 15 years.