Go to meetups in your area and start making contacts.

While it's always best to have a plan for how you are going to execute your exit strategy BEFORE you get started, if you're like me and just jump in you could easily find yourself wondering how to execute this plan if your initial plan runs into problems.BP is full of great advice on refinancing and if you just post that is what you're looking for, the vendors will come out of the woodwork. 

Those that respond “$0” or something ridiculous, you can request income documentation from them to justify.Don’t be afraid to share with them how much your property taxes & Insurance increased and that YOU cannot afford to absorb them.ALWAYS get an increase or something of value annually or tenants will start thinking they should never have an increase, making future increases that much more difficult to negotiate.

I live in San Diego and Im also looking to start investing out of state with little to no experience.

That will give you a good baseline to start from.You can also use AirDNA by buying the specific area to drill down farther.Try https://www.awning.com/airbnb-estimator as well.

b) How do i get started (like find properties that fit my criteria/constraints and then vet them, given I will likely be out of state) ?

If you know anything about building in Philly the plans and permits can be the hardest part of the project with it often taking many months to get everything in place just to be able to start construction.

Do this first deal to completion before starting the next one to see if it works out. 

I am a living example that real estate, starting from practically nothing, can take you places.

But I would start looking for your entry path.