Decisions need to be based on personal needs, but we can comment on the ETFs specifically. VFV represents the S&P 500 index, one of the broadest measures of the US market. We would consider it a very good ETF for an investor seeking long term growth from the US market. It is one of our favourites. VGRO is a mix of stocks and bonds, with 20% bonds. Thus it is a bit more conservative than an all-stock ETF. It is 40% invested in the US so there is some overlap with VFV. But it is a very solid ETF, in our view, for investors who still want a growth tilt. We would be happy buying either of these today. However, for a new investor, we typically suggest a staggered buying approach, perhaps over six months. While it has been shown that a lump sum results in better returns long term (because stocks go up over time), we have found that a staggered approach is easier for new investors, as it trains them to not be scared so much of market declines (as they will be buying into the decline). This can help them stay invested for the long term, which will result in much better performance than an investor trying to move in and out of the market consistently.
Authors of this answer, directors, partners and/or officers of 5i Research and/or affiliated companies have a financial or other interest in VFV.