Welcome to our new contacts system! You should be able to advance through all of your contact pages, but one thing that may help is changing the amount of contacts displayed from 50 to 500. This option can be found at the bottom left, just below the listed contacts.
Can you provide some more information on what is happening when you try to advance past page 9?
As for adding several contacts at once, we still have the same options, they are just found in a slightly different place.
From the List view page you will want to click into an existing list, or create a new list, and then click the blue Add Contacts button. You will see these familiar options:
If you are looking at the Contact view all you need to do is click the blue Add Contacts button and you will see an overlay like this: