World changes and random spawning of mob, NPCs

Yesterday our world was fine, login in today and the water next to my house has decided to receed, an iron golem spawned randomly in my house. One of the grey mobs from an underwater guardian temple decided to spawn in the water next to my house and as i went to take a picture a random quid spawned in front of me. I logged back in to llamas or alpacas inside my house and a snow golem thing aswell and my house covered in snow. Random creepers were blowing holes in my house even though i was not near them and i was inside my house and i left my house to come back and find there were spider webs in one corner of my house even thought the world was on peacefull. Also there was a random mountain next to my house that was covered completely in lava. Another thing was that when i was on ym roof fixing it, in peaceful, i turned and a creeper was glitching in and out of the game and i walked into it and it knocked me off my roof.