i want to patent an idea should i get a lawyer?

You figure out how to implement your "idea" in the form of an invention (a "new and useful process, machine, manufacture, or composition of matter"), fully describe the best mode for carrying out the invention, with drawings, and submit it to a patent attorney for "preliminary searching" for anything similar, finalization of the form of the specifications and claims, and for submitting it to the patent office with the proper forms, declarations, fees, and other required formalities. They then alert you when you have a "patent pending" and help you with the inevitable rejections and objections until your amended application is granted as a patent. This should cost you about $10,000, depending upon the complexity of the invention and how well you describe your unique contribution to the state of the art. You would then proceed with the similar amendments for any other applications you have filed in other countries where you might also want patent protection, paying the necessary filing fees in each country and submitting any translations, among other things. You then schedule the periodic post-grant fees to maintain the enforceability of your patents in each country, assuming you haven't yet sold them to others by then...

Yes and you can't patent and idea you can patent a thing. Example, I have an idea for a box that will make you young again. That is patentable. But if you actually design and build such a box you can patent it.

You get a patent lawyer. Give them all your drawings, plans, descriptions etc. Patent lawyers are some of the highest paid, and for good reason.