This is a regular verb. It follows the conjugation pattern of the verb falar.
In both Brazilian and European Portuguese, namorar means to date in the sense of being in a relationship.
In European Portuguese, more casual dating may be expressed with andar com.
Present:
A Ana namora o Miguel.
Ana is dating Miguel.
Imperfect:
A Clara namorava o João no ano passado.
Clara was dating João last year.
Conditional:
A Beatriz namoraria alguém do trabalho.
Beatriz would date someone from work.