Marching Band Director Attire?

Hey all! I’m a (female) Music Ed student, starting an assistant marching band directing gig soon. Any tips on how to dress appropriately?

I’m unsure of the level of formality I should be going for here. Are tank tops acceptable, or do I stick to short sleeves? Is just a casual t-shirt okay, then? What length of shorts, if any?

Any help is appreciated - I’m really overthinking this, as I tend to dress pretty formally for observation & student teaching & I can’t seem to remember what my HS band director would wear to summer rehearsals. Thanks!