After you file

On the IRS website for the status of the federal tax refund it shows Pending?  Or does it show Processing?

https://www.irs.gov/refunds

 

After the tax return has been Accepted by the IRS (meaning only that they received the return) it will be in the Processing mode until the tax refund has been Approved and then an Issue Date will be available on the IRS website.
See this IRS website for federal tax refund FAQ's - https://www.irs.gov/refunds/tax-season-refund-frequently-asked-questions