Welcome to these forums and I hope you enjoy your new phone when it arrives!
To avoid repetition there’s a great post which will help you find your way.
While it doesn’t have a specific link to iPhone apps, there is one there that will point you towards Sailfish equivalents for Android apps
There’s a link to the Community News tag for this forum, but I would suggest going further and just subscribe to the Announcements category:
One way to keep abreast of Jolla’s posts - including Phone updates and OS releases is to go to Announcements - Sailfish OS Forum and click on the bell in the top right. I have the ‘Watching First Post’ selected, and every time they make a new thread i get emailed an update.