I want to make my own keyboard can anyone help me with that I'm a bit new to arduino
Easiest is to use an Arduino that can act as a HID; e.g. Leonardo or Micro.
I don't have that I guess I'm using an arduino uno is it possible to do it with uno?
Seems to be possible; never done it myself. You need to modify the program in the 16U2 (USB chip). Do a search for "Uno as HID".
Not sure why you'd go through all the work (hours, to days, to weeks, depending on your skill) to make it work on an Uno, when you can buy a micro for about $5, use the Keyboard/Mouse library, and have it working in minutes.
Regards,
Ray L.
what is the real diffrence between uno and micro?
Different main processor; Uno uses 328, Leonardo and Micro use the 32U4.
How it affects your application depends but for a keyboard it probably does not matter.
Bastago:
what is the real diffrence between Uno and Micro?
I'm no expert but I believe, other than the Atmega 328/32U4 difference, the Uno has an additional chip to make for uploading programs via USB easier. It is my understanding that this additional chip limits the Uno's ability to act as a proper USB device.
Just having used the Pro Micro, I managed to get it working eventually, although it definitely was more of a PITA than the Uno. If I uploaded a dodgy sketch, overwriting it could be very difficult and take many attempts. I often had to follow this procedure to get it working again: Pro Micro & Fio V3 Hookup Guide - SparkFun Learn.
At least the 16U2 on the Uno can be reprogrammed 
Clone boards with CH340 or FTDI can never be used as a HID.