Hello! I was in your shoes over a decade ago, so thought I would add my two cents, in case it is helpful. I have a B.Sc. in Chem, studied law at UofT, spent my first few years of practice at a Bay Street firm, and am now practicing at a mid-sized regional firm in Western Canada.
I did not participate in the 1L recruiting in Ottawa, but can confirm what TheScientist101 said about 1L recruitment in Toronto. At the time, if you wanted to article at an IP boutique in Toronto, you essentially had to secure a 1L position at the boutique, as they would typically do most of their hiring at 1L, and keep those students through to the end of articles. And, in those days, it seemed to be a requirement that you needed an M.Sc. or Ph.D. in your technical discipline, in order to get into a boutique firm (except for, perhaps, those with engineering backgrounds, for whom a B.Eng. was often sufficient). I tried to get hired at an IP boutique, and had a lot of great interviews at several of those firms in Toronto, but ultimately was not hired, and I think it was that I didn't have an advanced science degree that kept me out. All of my peers who did secure those 1L jobs, had the advanced science degrees.
On the other hand, I ended up at a Bay Street firm with a significant IP practice, and in hindsight I think that was the better option. In addition to experiencing many different types of IP work (from TM prosecution to assisting with M&A transactions having significant IP components, drafting licensing agreements, participating in patent, copyright and trademark litigation), I also had the opportunity to experience general corporate and litigation files, and access to CPD on a wide variety of topics. In the end, although I practice IP law exclusively at this point in my career, I think that the broader experience, in my earlier years, has made me a more well-rounded lawyer. This isn't to knock the experience at IP boutique firms, which offer a wide variety of exciting and engaging files to work on, but just offering some perspective on what it is like to gain experience at a general service firm. Many of my friends who ended up at IP boutiques found that they were sometimes pigeonholed into a particular type of IP law once they became an associate (such as, only doing trademarks, or only prosecuting patents for mechanical inventions, for example), which is another factor to consider, if your interest is gaining experience in IP law more broadly.
If you end up considering opportunities at larger firms with an IP practice, I found the key was to really do your homework and find out what type of work is available in the firm's IP department. Almost all of the large and medium, full service firms will claim to have a significant IP practice, but in some cases the "IP practice" amounts to a couple of IP lawyers who happen to do a lot of IP-heavy transactional work, and there is very little (or no) IP litigation or IP trademark/patent prosecution work. So, if you are interested in experiencing the various types of IP, you need to do your due diligence to figure out which of the full service firms you are going to target.
Also, don't be discouraged if you don't land a 1L position. There are few positions out there (such as in Toronto), and it is highly competitive. I didn't land a 1L job, so I found a research assistant position at the law school over my 1L summer, and then secured a good 2L position.
As far as interviews go, you should do everything you can to demonstrate your interest in IP law. I understand that Osgoode offers many extracurricular activities relating to IP, so I suggest you get involved in as many of those activities as possible. Take all the IP courses you can get your hands on (in the 2nd and 3rd years). Do the IP moot (I can't recall what it is called, but there is one). Write some papers, submit articles to the IP blog. And, at least before 2L interviews begin (if you don't succeed in securing a 1L position), try networking with IP professionals and find yourself a mentor or two. There used to be a group called the Toronto IP Group, which was a group of IP professionals based in Toronto, they would periodically hold networking events and I'm certain that students were able to get a membership and attend - these types of social events can be a great way to meet professionals in the field. Another way to connect with a mentor is to check into whether Osgoode has an alumni mentorship program. They had one at UofT, which paired law students with law alumni, and they would try to match you with your field of interest. Through this program, I met an IP lawyer who offered me some great advice over the years, and continues to offer advice and insight to me today, over a decade after we first met. If you connect with someone, be sure to follow up and invite them out for a coffee. Ask them questions about their career and what it took them to get there. If you schedule such a meeting, be prepared to ask focused questions and be considerate of their time. It sounds like a lot of work, and it is, but you would be surprised about the valuable career information and advice that you can gain from this type of networking. And if you are like me (kind of bookish and introverted), this won't come naturally to you... but it is a skill you can develop, and it is great to start building those relationships now.
Wishing you the best of luck! Ah, to be a student again...