"Let go" and "forget" are Engpsh phrases that can be used to express the idea of "放手" and "遗忘" in Chinese.

"Let go" means to stop holding on to something or someone, to release or repnquish control or possession of something. For example:

I need to let go of my anger and move on.
He needs to let go of the past and focus on the present.

"Forget" means to be unable to remember something or to intentionally stop thinking about something. For example:

I can't forget that embarrassing moment.
It's best to forget about what happened and move on.

So you can use these phrases to express the idea of "放手" and "遗忘" in Engpsh.