When I first started writing and had the same question/issue, I was told by my creative writing prof that a certain amount of movement is assumed and doesn't need to be stated. i.e. if the character's in the room, you can have them move about the room without having to reference the "walking" part of it, since it is assumed by the reader that the character is doing things inside the room.
Yep, agreed. In dialogue I throw in some small parenthetical actions here and there (sipping a drink, doing some random little gesture) just to anchor the conversation in reality, so it doesn't seem like talking heads, but you only
need to say what they're doing if what they're doing is in itself interesting or relevant (e.g. some gestures/movements tell you about the character, how they're reacting or something).
Now, when you're taking your character from that room to, say, his car parked at the curb, you'll have to show him walking, running, etc. out the door and down the sidewalk to the car. It's too big of a spatial jump to make with the reader's assumptions.
You do need to do SOMETHING to make that spatial jump, but you don't need to actually say "he walked to the car" or whatever. You can say "he slammed the door behind him and patted various pockets, looking for his car keys. In the car, he flicked on the radio yada yada..." And the reader knows that he left the house, got to his car, opened the door and got into the car, without your actually having said that. Another option is to leave a blank line between paragraphs, like so:
Paragraph where the character is in his living room yada yada yada, doing yada yada yada. He's racking his brains about such and such and can't believe he's in whatever situation and wonders if he should go talk to his girlfriend or not, and so on and so forth.
Paragraph where the character is in his car, driving to his girlfriend's house. Yada yada yada.
Leaving a blank line between paragraphs lets you make all sorts of leaps without having to spell out for the reader what happened in the interval. In the above example, obviously he decided to go to his girlfriend's house, left his house, got in his car etc., but you don't need to
say all that.