Connection and MarketPlace World issues

Hello to whom this may concern. I have recently been having issues with multiple different systems on Minecraft. When trying to play with a friend, they would get stuck on a "connecting to multiplayer" screen and even worlds never being able to connect. I unfortunately can NOT join any of my friends worlds. This has been a reoccurring issue for a VERY long time and got to the point where I had to reach out. On the other hand, my Festive mash up pack- 2016 from the marketplace will not let me in the world, nor use any of its texture packs. I really hope me reaching out will fix these issues. I truly enjoy every memory this game has given me and I would love to be able to continue enjoying it for many more years to come.