@JC Chavez
I would encourage you to build rapport with a local lender or property management company that specializes in Multifamily. You can then, after you have a relationship, ask for CoStar reports to see rental comps and sales comps. Some states, like Texas, are non-disclosure states, so please keep that in mind. You may not be able to see past sales comps.
I agree with all the other great info shared above. Your asset is always going to be valued by your NOI and Cap Rate. In today's market conditions, it is not uncommon that you are purchasing based on upside vs actuals, so please be aware of that and ask yourself if your investing thesis aligns with this. For smaller deals you may be taking down yourself, you can potentially absorb that risk. However, if you are planning on bringing on JV partners or Syndicating a larger asset, you are then becoming a fiduciary of other investors' money; you don't want to take unnecessary risks on upside unless market data supports it.
I personally would advise on your underwriting when considering what offer to make you should factor in some vacancy expectations. I think it would be a gamble to assume 100% occupancy 365 days a year on your underwriting model and assumptions. If you're newer and sending your proforma to a lender and they see 0% bad debt, vacancy, loss-to-lease, etc, you are going to be giving off some red flags - it's an aggressive assumption to assume 0% vacancy for an entire year.