其实别人懂不懂得你的悲伤并不那么重要，重要的是你自己能不能理解你的悲伤，自己是否愿意接纳你的悲伤。加油！

The meaning of these 4 expressions is quite similar.  The main difference  will be 譬如/例如 are more likely used in formal situation. And 比如、比方说 will be used in informal situation. 

It is nice here. Good day to meet friends .

I feel that you need to ask you self what  you really want to learn. I mean if you just want to communicate( talk ) with Chinese people. Then listening and speaking will be enough for you. 

个人经验，跟我一起学习的伙伴蛮好的。 但不排除有你所提到的居心不良的人存在。