Allah did not Create 7 Earths . He created 7 Skies and Earth . Whenever you will read in Quran about creation of Skies and earth , you will read " KHALAQA AS'SAMAWATE WAL'ARDH " means created Skies and earth . Read yourself in quran :
Quran : 10 : 3 , " Indeed your Lord is Allah ...
To Brit ,
The best way in my view is to Read English translation of Quran and Books on Beliefs / Faiths in Islam and when questions come in mind then ask some learned Muslims or post your question on the site. Try to read quran , quran.ksu.edu.sa
I am from Islamabad, Pakistan. I am Muslim by birth. I am Master of Computer Science , Software Engineering [ MCS ]. I have been working in Saudi Aramco, Saudi Arabia. Now I am living in Islamabad,Pakistan.