A round is 5 seconds, so the average BMR is 20'/rnd. That's a shorter round than previous editions, which means less movement per round.
You can move while taking any action, but the action incurs a pace penalty based on how fast you are going. Creep = 0.5xBMR, -0. Walk = 1xBMR, -25. Jog = 2xBMR, -50. Run = 3xBMR, -75. Sprint = 4xBMR, you can't take any other action except one instantaneous action. Dash = 5xBMR, you can't do anything else at all. Those penalties for walking, jogging, and running can be offset with the Footwork skill.
It's also possible to expend some of your AP to move, and then stand still while taking your action, in order to not suffer that pace penalty. But the numbers are such that the penalties for attacks are the same (e.g. spend 1 AP to move your BMR, then make a 3 AP attack which will be at -25, just like walking).