Can you give an example of where you heard this? As far as I'm aware, there is no three-word phrasal verb 'get up with'. If you say 'I got up with Sam', you are simply using the normal phrasal verb 'get up' followed by the preposition 'with'. You'd say this, for example, if you and Sam were sitting in a waiting room, Sam got up and you got up ( i.e. stood up) at the same time.

Phrasal verb. La dovresti contestualizzare. Comunque vuol dire: Contattare qualcuno per telefono I tried to get up with you. Ti ho provato a chiamare. E' usato come slang

Hello Alessandro There are 2 possibilities that I can think of depending on the context. To 'get up' means to get out of bed in the morning. You can 'get up with the lark' (a type of bird) which means to get up very early or you can get up with the hump which means to get up in a bad mood. Hope this helps Bob