Hey @David Najera
My congrats, too - on your first purchase / first business! You've started on quite the adventure - with tenants - business - regulators - utilities - you name it! If I can, let me make a few suggestions:
First, please check with the city's planning department on the master development plan and the specific zoning for your address - to see if the business use you envision for this property is allowed - and what restrictions may attach to the use if it is approved.
Next, check with the planning department about the conversion of the garage to a studio (I assume you are talking about a studio apartment - not just an artist's studio). Can it / must it have an exterior door - separate from the access you might retain (or not) through the house? What would be the plumbing, electrical, and other requirements for a studio apartment such as you envision? Can the plans filing and work be done by you the owner modifying the property for your own enjoyment - or, at this scope of modification, must it be done by a licensed general contractor? Would the answer to the last question change if the property is a formal business and its modification is being done for business use reasons - rather than a personal use reasons? ... etc.(?)
Then, explore the permitting and inspection processes for such a conversion, if allowed by the master plan and zoning for your property. These steps will tell you both time and dollar cost for the legal conversion you envision.
If it is a go (either as a declared personal use or a declared business use at this point), get yourself and the property insured for all perils including construction perils for the period of modification. If it is a business use modification, additionally set up your business entity (or entities) so you achieve both personal and business asset protection and business operating capability and put the ownership of the property in the appropriate asset protection business entity and appropriately ensure your business operating and asset protection entities for all perils including the construction for the period of construction - before construction starts.
Once you have accommodated all of this information and tasks, either:
1. plan, file, and do all of the work yourself, have it inspected and get the occupancy certificate ... and then begin your 'business' (renting it out) - if this is your plan and it is allowed under the declared property use, or
2. plan, file, and have all of the work done for you by the various trade contractors/handymen you hire and once done, have it inspected and get the occupancy certificate, if this is your plan and it is allowed under the declared property use, or
3. have all of the plans, their filing, and the work done and supervised by a general contractor, have it inspected and get the occupancy certificate - as required for your situation under the local business, building, and construction codes.
Finally, get your business license and begin/continue the marketing and renting activities to fill your property with tenants who meet your standards (as described by others above).
Bottom line - this is a business - which is regulated for good public policy reasons. Be legal. And within these constraints (which all really have to follow) make money!
Cheers - Art