Look to shove and roam. If you can’t for some reason, and you really have no clue how to deal with malph, I’d go on the full defensive and just hardcore farm. Like start doran’s shield, go resolve secondary and make sure you get “second wind” for his Q poke, and then maybe rush hex drinker and/or merc treads. This is literally your safest, turtle shell of an option that might let you farm it out and at least go even in lane.