and if your going straight forward in a crossroad? I can never remember if you go to the right (or is that to go right) left? (to go left?) and do I need to filter?
For maximum visibility one should enter a junction in primary (middle of the lane) and proceed in primary until clear of the junction.
This is achieved by taking the position well before the junction: if you are on the left, in a cycle lane or not, look backwards, try to make eye contact with the driver behind, clearly signal and move to the middle.
If the first driver does not let you move, try again with the next one.
Sometimes there are Advanced Stop Lines (ASL) or bike box where you can filter to, but filtering is not obligatory, indeed sometimes is safer to wait behind a car or two.
Whatever your intended direction, you should always arrive at a junction in the middle of the lane, even when turning left.
It can get a bit intimidating, because cars don't like being slowed down by cyclists, but you'll get there!