My private parts are red inside

You don't give much background information (age, country, activity), but it could be Thrush, or an allergic reaction. You don't say where you are from so I don't know what might be available in your vicinity.

If it were Thrush, then an anti-fungal cream would be appropriate. I would advise medical attention if this is your first occasion. Self-help includes live natural yoghurt with pribiotic cultures.

1. Keep the area cool and clean.
2. Wipe from front to back; never the other way round (to avoid contaminating your vagina). Don't use a cloth when washing your genital area; it may harbour germs from last use.
3. Avoid scented soaps.
4. Ensure underwear is thoroughly rinsed after washing. Use only 100% cotton underwear, but when possible/practicable wear no underwear under skirts/dresses. Clothes that trap moisture, such as close-fititng trousers or knickers/panties made from synthetic material create ideal growing conditions for the fungus.

I hope this helps as a start.