How can I learn to "flirt"? Can someone give me pointers"? Not trashy just, nice & simple?

Having been in a relationship from the age of 19, that lasted over 23 yrs. I haven’t had to flirt and don’t have the first clue how to do so. I wanna get out into the real world and mix and mingle and if I find someone attractive to the things I am looking for in a new mate, how do ya go about it? I am a people person and love conversation but when it comes to letting him know I care about him, I am nervous as all get out. I don’t wanna be a trashy flirt, I am a reserved person. What advise can you give to me and other single moms/dads that have not been in the dating world for MANY years? Thanks!