clothes, shoes for 11yr old (76106)

Anyone can help me to get clothes and shoes for my 11yr old nephew he has hardly any pants and his shoes he is wearing are from the first day of school. So please anyone can help would be awesome. We are taking care of him and his little sister that is 7 due to Cps and anything would help. In search of 12-14 size pants med-l shirts and size 5-6 shoes for him and size 6x in pants and shirts and size 13 to 1 in shoes for her