Can't move when play through main menu?

Sorry for it being so late, and such a long and specific question, but this is really irritating me. I’m very new to UE4 and am basically following tutorial after tutorial on YT, I’m getting the hang of it though… Well except this bug… Anyways, I’m using the ThirdPerson Blueprint, except I changed the Starter character to one I made for my game, so when I press play being in the world I’m building it loads the world and I can move around and everything works like it’s supposed to (I have a nav mesh set which is what you’re supposed to do right?), BUT I created a main menu and it functions correctly! (Except I don’t know how to put a back button to go back to the main menu in the options tab???) but, when I click the start game button it takes me to the world and I can see clouds moving and grass flowing, but I can’t move my character, I can’t even look around or anything the camera is just stuck in place??? But why does it move correctly playing just from the world??? I have a feeling it has something to do with the play button itself, but I can’t figure it out for the life of me! Please help!