How to be prepared for my period?

So I am 13 and I have been experiencing all the period "symptoms" and I feel like it will be here soon. And heredity proves that! How can I prepare myself at school? I have been wearing pads every day because of dishcarge but thats it. My teachers don't let you take bags or anything to the bathroom and I don't want to go to the bathroom during passing period because there is not enough time and all the girls do their makeup in there and that would be weird. Since I am out and about shopping quite abit I have put pads, liners, anti bacterial lotion, underwear, and quarters. So please help me how do I prepare for my period? And what do I do I mean I cant take my whole bag or a little makeup bag for one because since the teachers wont let you like I said and two kids stare and stare? Thanks!!