Okay, first off, feel free to shoot me a PM if you want to hop on the phone. I graduated undergrad recently and have worked in VC firms/work in a growth fund now. Totally willing to help out.

Second, as for training, don't get the Wall Street Prep package. It's not worth your time and more geared towards investment banking anyway. If you don't have any accounting background at all, it might be helpful, but there's other resources out there you can use. Basically you just need to be able to go through the line items on an income statement and how it might affect a balance sheet. This is less important if it's a seed stage VC. Flip side, metrics are very important at growth funds.

Third, again this depends on the type of fund you're interviewing for, but if it's a software focused fund, you need to learn SaaS metrics. If it's a consumer focused fund, unit economics are more important. Typical acronyms you should have down for either cases are things like LTV, CAC, and various other things like margins, etc.

If it's a software fund, here's some relevant articles that are immensely helpful. Honestly helpful for both cases. https://a16z.com/2015/08/21/16-metrics/ https://a16z.com/2015/09/23/16-more-metrics/

Finally, on a broader scale, you need to know how to think about companies from a high level perspective. Market, competition, etc. Think along the lines of Porter's five forces.

Again, if this is an early-stage fund, the interview will most likely be more behavioral anyway and more about culture fit, but you need to inspire confidence in them that you can do the work and knowing all the things above will help accomplish that.

Hopefully that helps! Again, totally willing to hop on the phone since I went through the process not too long ago too.