20amp breaker but only have 15 amp recepticals?

I do woodworking in my garage. I have one dedicated 20amp receptical. The other recepticals in the garage are 15amp but the breaker for the (garage and living room) recepticals is 20amps…

Can I just get some sort of plug converter so I can plug in a 20amp plug into the 15amp receptical?

I need to be able to put a piece of equipment that will draw 17.8 amps on a different receptical.

The dedicated 20 amp is for my table saw and the other outlet I need to be able to put my dust collection system onto.

If your equiment draws 17.8 amps, then you need a 30 amps circuit/receptacle. Get an electrician.

Go to lowes/Home Depot and buy an appropriate gfci receptacle. If you do woodworking I’m sure you are handy and can change it out easy https://www.lowes.com/pd/Hubbell-20-Amp-125-volt-White-Indoor-Gfci-Decorator-Wall-Outlet/1000050447

The NEC requires 125% protection of circuit load so if you have a 17.8 amp draw then you would need to account for 22.25 amps. You need a 30 amp circuit breaker and 10 gauge wiring.

*This is my opinion based on the theoretical info given. My answer is “hire a qualified electrician”.

Did the dust collector come prewired with a 20A plug? If it required a 30A circuit, the manufacturer would have installed a 30A plug on the dust collector.
Pull the receptacle to determine what size wire is feeding the outlet. If it is 14 ga. you are out of luck unless you want to pull in new cable. If it is 12 ga., replace the receptacle with a 20A.