Usually you will get a letter in your portal account roughly 24 hours after your submission. That letter indicates that you can work until waiting for the decision (It has 4-month expiry date but you are allowed to work beyond that if you don't receive the decision by that date). Even if you don't receive that letter, you can just check your eligibility to work by checking criteria listed on IRCC website. If you meet all criteria, you can lawfully work while waiting for the decision. Currently, PGWP applications take more than 120 days to process. Due to backlogs, there is currently no sign for improvement...Unfortunately.