Looking to approach a girl ?

What's the best way I can approach this girl.I wanna ask her out.but my problem is I don't wanna just show up at her doorstep looking dumb.by the way I notice her when my brothers dogs ran away too her house an we met.she's not married lives alone but dnt knw if she got a bf.what's the best way I can handle it.wanna try asking for friendship atleast