I'm just starting out with a STR and I'm in the process of vetting companies for tax strategy and asset protection. 

Would it be best to start an LLC or sCorp in CA and deal with the astronomical annual fees?

When it starts to rain in monsoon season, put your galoshes on. ;-)

Thought I could set up an SDIRA and use this to get started.

Quote from @Arron Paulino: I had to remove four of my out-of-state properties in order to refresh the listings and start anew.

I started off wholesaling and I closed on 7 properties.

or it’s better keep as is with small updates doneI'd start by speaking with an architect or local permit expediter, then someone at the City. 

What kind of account or vehicle would you suggest to start saving down payment money for my first rental property?

Obviously some people started some of the fires.

Timing will make a big difference leasing this SFH in Seattle— if possible, aim for your vacancy to hit the market ~May 15th to June 15th, maximizing time on market for a June / July lease start date— this will give you the largest tenant pool, lowest vacancy time & highest rent.