I want to change the tyres on Voodoo Marasa
Changing tires will help - but probably not as much as you want. The annoying truth is likely simply that the people passing you have lighter, more efficient bikes and are fitter and stronger.

That said, you can definitely decrease your rolling resistance with narrower tires, with less tread, running at a higher pressure. The narrowest you can go is limited by your rim width. There are many rim with vs tire width charts out there you can consult. Manufactures also specify minimum and maximum rim widths for their tire models.

A 28mm road tire is probably as narrow as you want to go on your bike, even if your rims allow narrower. Be aware that narrower tire affect ride comfort significantly.

Other things you can do are: make sure you are not running pressures that are too low for road use in your current tires; make sure you drivetrain is clean, lubed properly and not worn out.