was wondering how i can adjust the pressure sensitivity and size in krita.

Global Pressure Sensitivity can be adjusted on: Settings > Configure Krita > Tablet Settings.

You can add points to the graph by clicking on it, or remove points by dragging them out of the graph.

The line on the graph describes how Krita treats the pressure inputed on the tablet.

The X axis represents the pressure input and the Y axis represent the output value.

You can also change the pressure curve per brush.

Take a look there: https://docs.krita.org/Parameters#Size