@Tyler118, you're getting good advice here.
I'd invest rather than make early mortgage payments, but if married, be considerate of spouse's feelings - marriage is more important than any other choice, you need a path you both can live with. If spouse would feel better paying off mortgage first, I'd consider it strongly.
Since you're new to investing and parents have advisors, here are other tidbits.
1. If you want someone to talk with professionally in person, Fidelity is another good company, and they have in-person offices. Like Vanguard, they are primarily an investment brokerage (a place that sells investments). They are almost as cheap on fees, but with the advantage of in person consultations available.
2. Vanguard has a service where they will invest for you (effectively, give investment advice) at a lower price than most. It's about .3% of your investment where many advisors cost 1% or something like that. Still expensive compared to coming up the right answer yourself, but if you're truly uncertain, .3% for a good answer could be better than a bad answer for free. Fidelity may have something similar. It's different from them explaining what a given investment does and what it's terms are, which either company will do. Just an option for early stage reassurance.
3. If, to reassure yourself or a parent, you did actually intend to pay for advice, the best route is probably a fiduciary financial advisor with a fixed fee and a legitimate professional certification. You might pay one or two thousand dollars for them to analyze your information, but they would be not taking fees from other parties. If an advisor is not a fiduciary, they can take fees from the investment companies and sell you weaker investments. Fixed fee is probably cheaper in long run than a %.
https://smartasset.com/financial-advisor/certified-financial-fiduciary-cff4. Doing it on your own like we do here is cheapest and can work great, you just have to learn. Fwiw, Fidelity has an equivalent of just about every Vanguard fund. FSTVX is the Fidelity equivalent of VTSAX.
I don't want to bog you down with choices, just giving you background. VTSAX if your spouse is comfortable is a great way to go if the two of you accept that the price will fluctuate.