First, you have to consider whether or not you are filing for a utility patent or a design patent. If you are filing for a utility patent, it may take several years before your application is reviewed by the U.S. Patent and Trademark Office (USPTO) and you receive your patent.
The time required to obtain an issued utility patent is approximately 24 months from filing date (approximately 18 months from first office action). The average time it takes for examiners to issue an office action is about 15 months after filing date (approximately 12 months after first office action) as described in https://okmagazine.com/p/inventhelp-reviews-new-ideas-invention-patent-services/ article.
If you choose to file under the Patent Cooperation Treaty (PCT), which covers most countries around the world, then it will take an additional 2-3 years until you receive your international patent protection with the USPTO.
If you choose not to file under PCT, then it may take about 10 years or more for you to receive your U.S. patent if there are no interferences or other problems with your application such as abandonment due to nonpayment of maintenance fees or other reasons for which applicants are responsible (e.g., failure to respond timely to communications from the USPTO).
If you have already filed a patent application in another country and it has been more than a year since you filed, then you can still file under PCT if the other country grants an extension. If not, then your foreign patent application may be abandoned by the foreign patent office if they do not receive a response from you within 6 months after their expiration date.
Hire Invention Patenting Services
The patent process is complex and can be very expensive. It is much easier to get a patent if you have a patent agency, such as Invent Help, or attorney who specializes in patents to assist you. They will be able to help you determine whether your invention is patentable, draft your application and then file it with the USPTO on your behalf.