Help me understand Exploration for newplayers

Currently I am trying out WH Exploration. I have been going around trying to find Data and Relic sites.

My question is: How are people dealing with Rats in these Data and Relic sites as a Heron? Do you only go for Sites that are completely empty?

I saw one video where they said to kite the enemies out until they are at least 120km away from the loot, but then some sites seem to randomly spawn enemies. Like... How am I suppose to know that that site is going to do that....?

I am very confused