Before I put a date on anything in Woodinville, I find out which permit office covers your address, because that decides how the schedule runs. Inside city limits it's the city's Development Services, which handles permits, permit review and inspections and takes most applications online through its Permit Portal. For parcels in unincorporated Snohomish County, Snohomish County Planning and Development Services issues building permits and clearing and grading permits. Once I know the office and what your project calls for, I tell you plainly who'll handle the permit and the inspections, and the pour date gets set around that review and the curing time the new slab needs.
Washington requires every construction contractor to register with the Department of Labor & Industries and to be bonded and insured, and on a residential job of $1,000 or more the contractor has to give you a disclosure notice from L&I, so ask anyone you're considering about both. The city requires a business license from any business with a place of business inside its limits, and from one based elsewhere when its yearly sales or income in the city run over $2,000. The state revenue department's page puts it differently, listing no license for $0 through $4,000 and a $39 fee above $4,000. On price, what moves it here is how much old concrete comes out, how deep the base has to go, the slope and drainage work on hillside lots and the finish you pick, and it's much the same story next door in Union Hill-Novelty Hill.