[Seeking Advice] Starting a coffee shop, & know almost nothing about construction.

A friend and I are trying to start our first coffee shop. This is our first time starting a business, and our first time building out a shop. We only have enough credit for about a 50k loan, and that needs to cover equipment (we have some), lease terms, architecture costs/city plans, materials, and construction. We really only have ~10-20k to spend on the build-out after the other expenses are accounted for.

We have a site on lock and are about to sign the lease. It doesn't need a lot of work to become bare-bones functional, but so much of a coffee shop is the vibe, so we are trying to figure out which materials will be cheap, but look good, and which construction processes will work well with the space, but we have no way of accurately assessing the site due to our lack of experience.

So I have some questions:

1. Should I shop around for contractors and bring them to the site?
2. What's the general process look like/What should I expect?
3. Does anyone know a reliable, honest contractor in LA (Boyle Heights).