I'm due to get my period on Holiday?

I'm due to get my second period on Wednesday. On Thursday, I'm meant to go on holiday to Tunisia. If my period doesn't come on wednesday, should I still wear a Tampon? It's been recommended that I actually try a Tampon when I'm on my period, but I won't have a chance. I don't even understand how you are supposed to use them, like what part is meant to be kept in your body! I want to have fun on my holiday, please help me!