I'm a bit confused about what you want. First, you say:
Basically, I want to start a portfolio of all my photographs so I can show it to newspapers or colleges or for internships or whatever.
But then you go on to say:
All I want to do is showcase my work. I am not so serious about selling them or anything right now but all I want to do is to get noticed at the moment.
If you want to show it to potential employers and/or educators, that sounds pretty serious. If you just like posting pictures to a site for people to look at and comment on, Flickr is great for that. If you're trying to get a job, or get into a school, or get an internship, it's all about presentation. It's pretty brutal to say, but most 'professional' photographers have day jobs (with certain exceptions, such as wedding/event photographer, etc) and supplement their income with photography. Having said this, getting a job as a photographer (or internship, or whatever) will take hard work on your part.
I took a class in college that was essentially how to get a job. Basically, if you spend 5 minutes on your resume, don't do any research on the company you apply for, and don't practice interview questions, you probably won't get the job. However, if you craft your resume for the position you want, put together a portfolio of related work you can show the potential employer, research the company to find reasons why you want to work there, and practice for the interview, you have a much better chance at getting the job, even if you're less qualified. You can apply this same thing to photography. A Flickr site that just looks like you spent a few minutes uploading photos makes you look like everyone else. But if you spend time to make a nice looking portfolio, caption every photo, and simply make it look like you actually care about photography, you stand out from the rest, even if you aren't as good as other photographers.
You really need to decide exactly why you want to get noticed, and showcase your work. If it really is nothing too serious, then Flickr is just fine. But if you (maybe not now) eventually want to get a job in photography, or sell photos, or something like that, the $3.25 a month that Smugmug costs (plus a little marketing of yourself) is well worth the investment. At this point, I'm not sure you know what you want. People might stumble onto your photos through Flickr easier than Smugmug, but with a little marketing on your part, you will get noticed a lot more using Smugmug (or other sites, like Zenfolio).