How to tranfer contact and all my phone number from my old iphone to my new one?

I'm going to change from my iphone 5s to a new iphone 6 plus in the next couple of days and I really want to know how can I transfer my old iphone phone number and my contacts to my new iphone

Your phone number should automatically transfer if you switch the SIM card; that is also assuming you are keeping the same provider. There are two ways to transfer your old data to your new phone. Either use the cloud which is through Wi-Fi, you can find it in settings and make sure it says you backed your info up recently. Or you can physically plug it into iTunes and backup all your information so that when you get your new phone all you have to do is transfer from either the cloud or iTunes. Hope that sorta helped.