You've mentioned before on chrons that you have problems with basic grammar and punctuation, but no publisher is going to find that acceptable in a submission, so you would probably need something like a line editor.
However, that all assumes your plot and storytelling in itself is all fine, and almost no one gets this right without input from a developmental editor. Do be aware, though, that they will point out the issues and it will be up to you to rewrite these, they will not write out these for you.
So if you really wanted to throw money into this, a developmental editor, probably a couple of runs to ensure you get it right, followed by a line editor to point out what you need to tidy up.
Having 0 knowledge of writing style/acumen/experience, it raises the question of, Can you (Timben, not Brian G Turner) write a succinct 3 act outline of your story? If not, don't waste money on an editor: your story has core structural issues that need addressing before worrying about anything else.
Second, research the genre: have you hit the relevant genre expectations? (e.g. a Western without a showdown and everyone lines happily within the law) Are you within the general wordcount expectations? (plus or minus 5%) If not, an editor is still probably not worth the money.
Third: Have you started with alpha or beta reader? Have they said things like, I didn't understand what happened when... ____ plot point/character development/complication/ etc. If so, you may
still have some structure issues.
If yes to all three, then start with a development editor if you're not 100% sure your structure is great. There are also "story coaches" and other similar titles out there.
AFTER structure is set, do line and copy editing after you do 2 more passes. You'll find things. Use grammarly or ProWiritingAid. You'll find things
The editor will likely offer to do a few X pages. Send them over and see what kind of comments/questions/etc. they raise. Have a conversation. As much as you're judging them, they're judging you: writing with flavor, brevity and precision may get a lower rate. If they think they'll need to redline every sentence, that rate is going to rise.
I also love that your avatar is a Norm McDonald Burt Reynolds drawing.