Putting In Multiple Applications
Landing a job can take anywhere from a few days to a couple of weeks. In some cases, it can even take a few months. It all depends on the needs of the company and your current qualifications. So it is a good idea to apply with multiple companies to better your chances of getting hired.
Just remember to add their email address to your safe senders list after applying. Otherwise, their emails might land in your junk/spam folder.
Now if you don't receive any word back after a long while, it's most likely because the company is not currently hiring, has a long waiting list or you did not meet their criteria. In either case, it doesn't hurt to contact them regarding your application status.