Sensation tip of penis but not during urinating and prev itching of genital area now gone. Is this an STD? Not happening at once. Only 1 partner.

Unlikely STD. Itching in genital area is more likely related to contact allergy or possibly a yeast infection, especially if symptoms have resolved. A penile discharge or pain with urination is more suspect for STD infection. Either way, it is always wise to use condoms with sex and get baseline STD and HIV testing in individuals that are sexually active.