New Investor Advice

Hello,

Last may I finished college and landed my first Job and am ready to start investing. I currently make $2855 / month after tax (not alot I know) with a 4% employer match on a Group RSP with RBC.

I would like to start investing in ETF's and currently am looking at VEQT, VFV, VOO and VTI (though those last 2 may be out of budget currently) in a TFSA.

My questions are:

A) how much of my monthly income should I be investing? Currently my monthly costs are very low as I live at home.

B) Can I have my RSP invested in ETF's through RBC? Or is that not a thing?

C) Im under the impression that due to the state of the market now is a good time to get in. Is that true?

Thank in advance.