Ditch=to leave
I'm ditching. 我走了。
—Let's ditch, this party's lame. 我们走吧，这聚会不怎么好玩。
—Yeah, it is pretty dead. Where you wanna go? 对啊，真没意思，你想去哪里？

1. Let's ditch.=Let's go./ Let's leave./ Let's get outta (out of) here.

2. ditch school/ class=skip school/class

3. You're ditching me? 你让我一个人吗？
Don't ditch me.

4. lame=boring/ not interesting/ stupid

5. wanna=want+to
gotta=got+to