There is no up or down, north or south, west or east in space. so how do astronauts navigate say to the moon?

there not gonna say, well we go straight ahead, do a left, then take your next right turn obviously. so howd they do it? plus what if the y wanted to travel to mars. how would they get there. navigate there?. plus when astronauts go to the moon do they have to travel above the earth. is the moon higher situated than the earth? so would they have to keep goin up, leave the earth and go higher? or is the moon below us or on the same level? so if they left earth the shuttle would be seen flying below the earth towards the moon? sensible professional answers please