Just some quick thoughts off the top of my head.
1. Whether to pay down debt or invest is, in part, a question of the balance of returns. By paying down debt, you get an automatic 3.45% return (after-tax dollars). If you think you could invest that money and make better than 3.45% (in a TFSA so such earnings are tax free) then technically the prudent move would be to invest. The risk here is that as interest rates start to rise, this assessment changes quite quickly (I.e. you might be confident at 3.45% but in a year or two, it might be quite a bit higher) but you may not necessarily want to, or be able to, pull money out of your investments to react. If it was me, I would probably invest some and pay down some debt.
2. At $100k salary, you may want to familiarize yourself with the various tax brackets. IIRC there is a threshold at ~$88k (sorry I'm too lazy to look up exact amount at the moment) where your marginal tax rate jumps about 4%. Meaning there's a decent amount of incentive to contribute enough money to your RRSP to lower your taxable income back down to just below this ~$88k level. If you're at $100k drop $12k in, get tax return next year and throw that into the TFSA or debt.
3. Personally I believe, there's value in trying out the stock market/investing. One day you're probably going to want to be more active in investing, and I'd rather take my lumps with a few early $1k-$2k investments than later with the $10k-$20k investments. Get a feel for buying some shares, learn how to not panic when share prices go down, and to not get to excited when they go up.