Samsung Apps problems

[Rowdee1]

Sorry, new here and couldnt figure out where to put this. I have a Galaxy S2 Lite and after changing carriers I erased all info to start over. The old carriers crap is still stuck to my fone and needs to go. Need to get rid of all their crap. Also, Samsung apps decides to dump a bi Angry Birds banner rite on my home page in front of my daughters pic. Make it go away. I installed a root file reader and I guess I need to root the fone first to be able to uninstall some of the crap. Im not very educated in all this and could really use some help. Please.. and thanks.