Lag

Hi, I want to say some bugs that I found, if you can't understand some words it's because I'm translating through Google Translate, I'm from Brazil. So, when I enter the world I want to play, it takes a long time for me to enter and when I'm playing, chunks take a long time to load, besides that minecraft is lagging a lot. The bugs I found are: the profile pictures of my minecraft friends are not showing up, this also happens with my profile photo and the image of the achievements.