Database Migration confusion

Ok

Let me explain my confusion further.

Say I design and release an app, that makes use of many tables in a database. I,m assuming for each table, there will be a seperate migration with an up and down method. Each migration has the same timestamp.

Then I release an update with a modified schema. I create the migration file that just updates one table and (I'm assuming here) that this then has a different timestamp.

This poses a couple of questions in my mind.

For the original schema, if I have foreign keys in my tables, they will need to be created in a specific order, how can this be accomplished?

Then, if someone installs the app for the first time, all the tables will need to be created and updated, how is this accomplished?

Thanks.