I just got Krita and when I got onto it for the first time, it wasn't letting me do a brush stroke, so I exited the application and re-opened it, this time it was very lag-y and the brush stroke wouldn't appear until I clicked on the layer it was on. I'm not sure what to do so I just wanted to know, hopefully, it isn't something big.
Please select angle instead opengl in settings/configure krita/display. If that fixes the issue, please paste the output of help/Show System Information for Bug Reports in this bug. *** This bug has been marked as a duplicate of bug 360601 ***
I did that and it didn't change anything... I'm not sure what to do.
Try disabling display acceleration completely and paste the output of the bug info dialog (see help menu) in this bug report.