Help Determining What Can or Can't Be a "Place" and Using Onomatopoeia

[Peachesnscream]

Hi, I'm writing a kind of poetic piece for a contest, and a sentence I want to write is something like "in my dreams" as in, dream/s is a place where I see something/someone.
Can I directly translate it as ゆめに to mean dreams as a place, or is there something specific I should do?
Also, I'd like to include onomatopoeia, and I read that I can use it as long as I put と after the onomatopoeia (どきどきと), but I'm not 100 percent sure that's all.

I'm only in 102, so there's a lot I still need to learn, but I'd appreciate any and all help.

 

[Toritoribe]

Can I directly translate it as ゆめに to mean dreams as a place, or is there something specific I should do?

You can use ゆめ, but the particle differs depending on the verb.
e.g.
夢に出る（ゆめにでる）
Someone/Something appears in the dream.
夢で会う（ゆめであう）
You see someone in the dream.
夢で見る（ゆめでみる）
You see someone/something in the dream.

Also, I'd like to include onomatopoeia, and I read that I can use it as long as I put と after the onomatopoeia (どきどきと), but I'm not 100 percent sure that's all.

It depends on the function of the onomatopoeia.
e.g.
adjectival: どきどきのきもち
adverbial: どきどき（と）ときめいた

 

[Peachesnscream]

So just to clarify, if I wanted to write "In my dream I saw a man" it'd be:
（私の）ゆめに男の人を見ました。

 

[Toritoribe]

で is used to indicate the location of action ("to see"), as in my examples.

 

[Peachesnscream]

Okay, I should've payed closer attention to that particle.
Thank you for all your help.

 

[Toritoribe]

If you just see him from distance, 見る is a correct choice, but if you see him closely face to face, you need to use 会う.