Well…
If it’s just 2 of your fixtures, chances are they have something blocking the water way (gravel, excess glue, sediment, etc.) If you feel handy- check the KS aerator by unscrewing it- if nothing there move to the valve(s) in faucet itself- then the supplies- for the w/c remove top of the ballcock (you know… the part that fills the tank) & check for debris- turn the water off to the fixtures before attempting this-preferably at the meter as building shut offs & old angle stops at fixtures are not always reliable- if you can’t find any debris inside the internal parts of the fixtures then maybe remove the angle or straight stops coming out of the wall/floor that supplies those fixtures- if there is still no sign of debris then the blockage is in the pipe in the wall or under the floor (usually at a “reducing on run” tee)- call the plumber if this is the case.
good luck