Admin work, social media, online stuff, phone calls, pick up supplies from Home Depot, etc. 

Definitely shop around with a few mortgage brokers also.

Just trying to learn all I can.Any and all tips welcome as I feel like I just opened the door to a massive mansion of information with thousands of rooms to explore.

Specifically what are tips for choosing tenants that will live in harmony?

Tips on what to say or do next after some one calls you back from your letter?

Also, I typed into google, "We Buy Houses" and there are websites online that claim that they buy houses any condition.

So do your due diligence and make sure that the strategy you know works in California will work in other states as well.If you don't know the area, here's what you'll need:A local real estate agentA loan officer licensed to originate loans in that stateA local property manager (they should have repairmen, contractors, etc. contacts for you)It works best when you have local "boots on the ground" so to speak, meaning friends or family members who can keep an eye on the property for you... which your property manager can do for you, but for a fee.I would recommend reading BiggerPocket's book on long distance real estate investing for a ton of other tips as well: https://www.biggerpockets.com/store/long-distance-real-estate-investing-ultimateIf you have any questions about the Phoenix Metro Area market when you're considering which area to invest in, feel free to reach out and I'll try to get your questions answered or point you in the right direction!

I don't even remove my listing from online until I have a signed lease, and their funds have cleared my bank account.

@Bree BladesYou can send a certified letter so that you have documentation that you provided written notice to address on lease.You could also go online to your county Register of Deeds or Real Property services page and lookup the owner and send them a letter.

I'm working on lining up funding and I would like to put an offer in, but how do I do so, if they aren't responding?