It's probably not a great idea to show up in person and ask for an interview. That doesn't mean that you need to go through their bureaucracy to get a job though!
For any company that you're interested in, I would recommend trying to find a person who would be your direct supervisor if you were to get the job you wanted there and sending them a nice, personal email asking what sorts of opportunities are available at their company. Finding this persons contact information can sometimes be a bit of a challenge, but for most companies, some clever googling can get you close.
The great thing about emailing a human (rather than trying to go through the corporate bureaucracy), is that you're likely to get a human response. Even if they don't have a position open right now, they might be able to refer you to someone else in the industry. And, if they do have a position open, you'll have a contact to help you navigate HR, which can be especially helpful if you're missing some of their "required" qualifications.
I've used this approach in the past, and it totally works. It does require quite a bit of research and talking to quite a few people, but it feels a lot better than sending resumes to HR departments and never hearing back from them.
Another important piece of advice. I see elsewhere in this thread that you've "applied for a couple jobs." Given that you don't have any professional connections right now, you're probably going to need to apply for 50+ jobs before you get your first offer.
With that in mind, you absolutely cannot apply for one job at a time. If it takes two weeks to hear back from someone, and you're only applying for one job at a time, you'll be spending two _years_ looking for a job. Once you get out of the one job at a time mindset, it's totally possible to reach out to 5-10 people a day. You should be getting in touch with so many people that you need to keep a spreadsheet (or notes file, or something) to remember who's who in your job search.
Also, Don't let any individual rejection get you down, just treat is as another possible future connection and move on. Fortunately, when you're talking to 5 new people every day during a job search, it's a lot easier to not take rejection personally.
Good luck! I'm sure there's a position out there for you.
For any company that you're interested in, I would recommend trying to find a person who would be your direct supervisor if you were to get the job you wanted there and sending them a nice, personal email asking what sorts of opportunities are available at their company. Finding this persons contact information can sometimes be a bit of a challenge, but for most companies, some clever googling can get you close.
The great thing about emailing a human (rather than trying to go through the corporate bureaucracy), is that you're likely to get a human response. Even if they don't have a position open right now, they might be able to refer you to someone else in the industry. And, if they do have a position open, you'll have a contact to help you navigate HR, which can be especially helpful if you're missing some of their "required" qualifications.
I've used this approach in the past, and it totally works. It does require quite a bit of research and talking to quite a few people, but it feels a lot better than sending resumes to HR departments and never hearing back from them.