North node expands what it touches. So, if anything, having a north node/Venus conjunction would make Venus and what it represents especially big in your life.
We can also interpret planets on the north node as something that you're working towards, learning, or reworking. If we interpret the south node as your karmic past--past lives, or unconscious assumptions carried in this life--and the north node as what you're moving toward, a planet on the north node would represent what's hindered you in the past, and what you need to take in, or learn a new relationship to.
If Venus is on the north node, there might be a pattern of unrequited love, or wanting unavailable people, or issues around self image, body, how you handle money, or creativity and creating harmony, to name a few possibilities. But, it really depends on the rest of the chart, and how you yourself are living it. Whatever your Venus issues are, working through them is a lifelong task, and a recurring theme.
If you want a particular chart interpreted, you need to post the actual chart, not just birth information.