What cream do I use to treat skin fungal on my shoulders?

SEVERAL OTC. First, are you sure it's 'ring worm' (fungal infection)? Tinea corporis (skin fungus) is a superficial dermatophyte infection. Several over-the-counter creams are helpful but Lamisil (terbinafine) (or generic) tends to work the best due to it's cidal (fungal killing) action. A low potency steroid (hydrocortisone 1% or cortaid) can be added if there is moderate redness (inflammation) hope you are better soon.