Talk to your GC. S/he will advise you. Look at the list of your schools. Some will stipulate a math or English teacher, this year or last, so it can pretty much point who to ask.
You are not in an unusual situation. A lot of quiet students feel their teachers don’t know them enough to ask. The teachers will likely be ready to write refs -as it is part of their jobs. They will likely ask you to list things you want mentioned, reminders, events, just stuff that YOU feel would be beneficial in a LOR. ,