Christy, You can try a soft reset. Remove the back panel and pull the battery out.
Press and hold power button for one minute with battery out.
Install the battery and put cover on.
Try to turn the phone on and try to charge.
Since it is a newer phone If soft reset does not work, return it to place of purchase or the manufacturer for warranty refund/replacement/repair.
Check the attached link for more trouble shooting on the Gallaxy S2, instruction and guide, Good luck.
I hope this helped you out, if so let me know by pressing the helpful button.
http://thedroidguy.com/2016/09/how-to-fix-samsung-galaxy-s2-that-wont-turn-on-troubleshooting-guide-108917