New player, Have a question about vicious swing and combining feats/ attacks

Hello everyone! I had a quick question. When making a vicious swing, it says it counts as 2 attacks when calculating the multiple attack penalty. Does that mean using it has a -5 penalty to hit? Or that making another attack will have a -10?

Also, some feats (like brutish shove) say it can be applied automatically after a strike hits. Does that mean I can do a vicious swing and automatically apply a shove?

Any help would be appreciated! :)