On top advice please

Hayley • TTC baby number 1 for over 3 long years! Engaged to be married to my fiancée of 4 years
Hi everyone I'm 26 my other half is 24 we have been together 3 years our sex life has recently started to go down hill a bit I am looking for ways to spice it back up. My fiancée loves me being on top but I'm not comfortable because I don't really feel like I know what I'm doing and I tend to jus feel awkward has anyone got any tips or helpful answers on the best way to be sexy and good to your man while in this position please???