I am in Ohio. If I start engineering work for a project, does that constitute my first day on the job with respect to the timing of the Notice of Furnishing? Also, same question with regard to ordering material. Will that count as my first day on the job?
It is a good practice to serve your notice of furnishing on whatever day you make your way out to the site. Notices of furnishing must only be served by contractors who are not under contract directly with the owner, i.e. contractors under contrqact with the general contractor or someone else, so you may not even need to serve a notice of furnishing.
Additionally, as to the material, if you are performing multiple scopes of work on a single project, all of that work can be lumped into a single lien. For that reason, all of the work can be encompassed in a single notice of furnishing. Whether you start the engineering work or the supply work first, I would use that date as your notice of furnishing date and get the notice served on the owner.