[NEED HELP] Unabel to start xonotic in xubuntu 18.04

I am having a pc with intel pentium 4 with 3.01ghz processor 1gb ram 128mb dedicated vedio ram .i dont have any grafic card but there is intel integradted express chipset grafic card 910 G.i downloaded xonotic from software center and when i open the xonotic app a black screen comes up and nothing happens after that i have to restart computer to end it.i tried to run it through terminal and i get a big list "current nice level is below the soft limit- cannot use niceness"." Requested 1xAA,got 0xAA".and final line says restarting renderer.what should i do to solve this .i want to play xonotic on this pc