Should I be pre-approved before calling contractors, agents, or even analyzing anything? 

Usually something happens to the HVAC at the changing of the seasons, then you have to use one of the warranty company's approved vendors and wait for them to actually be able to schedule with your tenant, then they come out and diagnose and it's another two weeks before they come back to really fix it and they end up doing a bad patch job and have to come back out 2 months later, etc.Also keep in mind the limitations of a warranty.

First of all, the didn't ask me too many questions, they asked how much I need and where is the properties.Then the gave me a simple and not professional application via Word document and there as no section to put the ARV (As I am searching for a fix and flip).Gave me an approval letter without any mentioning the monthly payment, the interest that I'll pay...And finally wrote that I need to put 2% (2 points) BEFORE closing, the was the final red flag for me.Be aware of these scams

Review the R&Rs from your HOA ; I had to get my indoor garage storage approved. 

They will need to be licensed or your plans won't get approved by the HOA or city.

The loan got approved and appraisal done a month ago on 2/24.

Depends on the property, offer, who's approving, etc.Have you been pre-approved?

Purchasing my 2nd investment property and I financed with the bank. Were almost at the finish line and bank hits us with we need to see funds for downpayment in your account and it needs to show that's it's been there...

The trick is getting approved for grants and tax credits. 

(TBH, I only save rental income and am trying to build it to reinvest, but you see what I'm saying).Find other investors to learn from, get pre-approvals, get your documentation in order, and don't be afraid to ask for help.I've been incredibly lucky to find an amazing group of people here, and at home, that are incredibly generous with their time and knowledge.