So to begin to learn how to transmit weight and energy from the body into the cello, I will try to simplify the concepts that your imagination and body, within a feedback system of your intention and your sensing, can try out.
It can help to imagine that you are releasing weight downwards towards the floor. Beginners sometimes think you should press the bow inwards towards your body. It may look that way in paintings but it is better to imagine that the pull of gravity, a vertical pull, is relaxing your arms towards the floor.
There is a downward force on the string from the weight of the bow and from your body mass, but don't think of it as force or pressure. Please go to Cello Bow on String Basics for clarification on this vital topic.
Never squeeze or press the string down with only the fingers and thumb. This deadens the vibrations of the string and will cause physical problems throughout the body.
The bow arm needs to learn how to release muscle tension as it moves and balances through a stroke.
To venture towards the bridge, you need to add weight. This is not something for beginners to contend with. It's easier for beginners to increase the bow speed to get more volume.
When you can play a legato piece with vibrato, you are ready to try playing close to the bridge. I like the image of sinking into bread dough or thick chocolate pudding. You can practice this by doing "swells"
(Video demonstrating swells)