English name translation of "Sun Wenqi":
Sun, Wenqi (the surname will be distinguished by commas before the first name)
Generally speaking, the first name "Wenqi" is used before the surname "Sun":
Wenqi Sun (you don't need to use commas before the first name)
If you want to take another English name that is homophonic, you can consider: Wandel, Winnie
Because foreigners' pronunciation of pinyin is different from ours, some people will pronounce it slightly differently or even inaccurately, but this will not affect your self-introduction. You don't need to cater to their pronunciation to introduce your name.