I'm assuming you're looking for a bank loan?
This really isn't something you should outsource to a stranger on the internet. If you aren't comfortable writing one yourself I'd find an advisor (your accountant perhaps?) and look for a solution with somebody you can meet in person.
Loan officers aren't fools.
I agree with YourMoneyButton that you don't want to pay someone online to write a business plan. They are not really going to know the ins-and-outs of what makes your idea unique, etc. You could try to put your company's unique qualities and very detailed outline on paper for them, but it's really better to sit down with someone and spell out everything. Ideally, you want someone with experience writing business plans who knows what questions to ask.
I have written a few business plans and started with a sample I found online and spent about 300 hours molding it into something worthwhile. It took a lot of research and tweaking, but I finally got something that I was able to get a bank loan with. However, the do-it-yourself route may not be for everyone.
There are sites that offer free software/apps or online tools and templates for writing up a business plan without outside assistance (see enloop.com, planware,org, etc). The OP should complete a plan of proposal using those tools, or use them to create a first draft that can then be taken to an expert proposal writer, if outsourcing is still felt to be necessary.
No it's not for the bank loan.we are not born in US so our English is not better to write something like that.we tired with our accountant but his prices so high.Thanks for your Reply
If it's not for a bank loan you wouldn't need a formal business plan in the US. Who told you that you needed one?
I wrote one for myself earlier this year using the SBA free tool. I did it in an hour or so. You can probably get most of it done and then have someone go over the language https://www.sba.gov/tools/business-plan/1