I would start by researching properties on loopnet or other commercial property classifieds, then contact an agent, and express your interest in financing. (Even if you've already found the property you want)
Not having a business plan is kind of disheartening as even if you plan to not have your own business in the property, you still have to visualize your goal in converting the property to positive residual. (Location/Average Lease Rates etc), plus the lender might ask to see what the plan of the property is. But honestly this is not important in an early stage.
Also consider commercial properties can have great potential however you can have vacancy for quite sometime, as commercial properties don't lease as quickly as residential in most cases, and you need to be able to invest tenant improvement allowances for businesses looking to lease.
There are tons of sites out there that can help you retain the knowledge (bigger pockets is a forum, but primary is residential ) you need to get started. I would just take time to research your target market for investment, and figure out the location that can suit your financial goal.
But just shop Agents, as many as you can, there will be one with an excellent lender in their back pocket.
Good for you though, commercial property investment is awesome and I wish you the best!
Side note: Take the Mazer or Aston, commercial agents can be snarky, show them you mean business