Despite being very anxious about travel, I have booked a 5 days overnight stay in London for me and my daughter to celebrate her birthday. I haven't been in London in years, could someone help me what do I need to book to go to City centre from Gatwick Airport, what travel pass do I need. It was a bit step for me to book it as I am very anxious so I want to try to be as stress free as possible to avoid having panic attach and ruin the trip. Thank you