If there is a ripple in gravitational waves does that mean that time is slightly changing too but as we are in it we don't experience it?

>> ... time is slightly changing ...

Time at any one place always runs at the rate of 1 second per second.

An observer at one place (X) might observe time at another place (Y). In that case, the observed time doesn't have to run at 1 second per second, meaning 1 second of X time doesn't have to match 1 second of Y time. A gravitational wave at X, Y, or between them would change the observed time ratios.

An observer in far space would see time on Earth run slower by about 0.5 seconds per year. Gravitational waves are VERY weak, so a typical wave (like the ones in the news recently) would not change that enough to measure.