could not connect with the world

Hello, my name is Álvaro, I have been playing Minecraft PE for two years and for almost 9 months my cousin and I have been unable to connect to the world, we are tired of this error, we tried to uninstall the game and reinstall it and the first time was but we lost everything, please, if you could fix this error ... We tried to see if it needed an update but no, we have the same versions.