Once you have taken in the whole situation, you choose a safe speed appropriate for that junction.
Priority is the way it is regulated who gets to go through a junction first.
When another road user has the right of way, you must give them the right of way. Giving right of way means “allowing the other driver to go ahead in such a way that this person can continue their journey unhindered.”
So you approach calmly and brake in time so that it is clear to the other person that they have the right of way. Full braking at the last moment is not the right way to give right of way.
Many accidents happen at junctions. These accidents are often due to errors in giving way. People forget to give the right of way or take the right of way they think they are entitled to.
In traffic, common sense is most important. Approach a junction calmly and never take priority if you think you are entitled to it. By approaching calmly, we mean a speed that allows you to stop in time when necessary. And by taking right of way we mean simply driving through because you have the right of way according to the rules. Wait for someone else to give you the right of way and then drive on.