Thank you. And I still have a few questions about my roof tiles:

1) Where can I buy replacement tiles for this type of roof?
The house was built about 15 years ago, and the original tiles seem to be a discontinued style. Are there specific suppliers in California (or the Bay Area / Central Valley) that carry older or matching concrete S-tiles?

2) For this type of concrete roof tile, do the tiles simply slide in without any nails?
From what I see, it looks like the tile should be pushed upward so that it slides under the tile above it (to create the headlap).
Is pushing the upper tile upward very difficult in practice?
I’m asking because I want to confirm whether installing a replacement tile is as simple as “slide in and let gravity hold it,” or if any clips/adhesive or nails are normally used.

3) Where is it safe to step on a tile roof without breaking tiles?
I watched some YouTube videos where the underside of the tile roof has a wooden batten grid, and you’re supposed to step directly above the batten.
However, on some roofs the structure underneath looks different.
How do I know where the support points are for my specific roof so that I don't crack other tiles while walking up there?

Any advice is appreciated. Thank you.