Based on your needs, my personal suggestions are as follows, please refer to:
First, there are many large-scale clothing wholesale markets in Beijing, including Dahongmen Clothing Wholesale Market and Zoo Clothing Wholesale Market. Market, Yabao Road Clothing Wholesale Market. Based on your situation, I suggest you choose the Dahongmen Clothing Wholesale Market (the Dahongmen Clothing Wholesale Market mentioned here is a large area, including the entire Dahongmen Bridge from the Bairong World Trade Center in the north of Muxiyuan Bridge to the south to Dahongmen Bridge on the South Fourth Ring Road a street).
Second, if you want to find a more representative Beijing clothing mall, you should do your shopping yourself. It is recommended that you go shopping in Xidan Commercial Center. There are shops of all grades, as well as high-end shopping malls such as Scitech. Some small shops on the roadside are also good, giving you a wide range of choices.
Finally, I wish you a happy shopping. If you need any help during your stay in Beijing, I will be happy to help (at your own expense, haha).