The solution came to my mind is to quickly review the list of men English names and list of women English names, which helped me to be familiar with this culture specific feature. Having said that my name sounds unfamiliar to the other people as well.
Top 10 boys names:
Jack; Thomas, Joshua; William; Daniel; Matthew; James; Joseph; Harry; Samuel
Top 10 girls names:
Emily; Chloe; Megan; Jessica; Emma; Sarah; Elizabeth; Sophie; Olivia; Lauren
Is the problem fully resolved?
Because London is a multicultural city, knowing the English names only doesn't help because you might meet people from other cultures as well. So I guess the best way is just to ask the other person to spell his/her name.