Before you can enjoy using the mobile services of LTE, remember that you have to have an LTE phone with updated software to make it LTE-capable. Check your device manufacturer's website and look for your phone's features or network/frequency specs.
Also have an LTE SIM. Go to the nearest Globe store and obtain an LTE SIM for your phone. (You can still keep your current number even if you change to an LTE SIM).
Your current plan will work with LTE. You can also register to existing promos so you can enjoy unlimited and/or discounted services.