How much time should I spend in Velen/sidequest advice

I started playing about a month ago (yes Ive heard about waiting for the remaster) but this is pretty much the first game Ive ever played. I started playing, got through white orchard relatively quickly, and then got to Velen and Novigrad at only about level 4 was chasing the white hunt with Keira. Then I realised my mistake, and saw some advice on here to explore white orchard properly, so I sought out every side quest and object and everything I could before moving on.

Im in Velen now with much better gear and a higher level, but now Im trying to figure out how much I should go looking for side quests and how much I should follow the main story. It feels like Im completely ignoring Ciri at the moment and Im just going looking for contracts and monsters. Stumbled into the level 20 leshen a couple of days ago while on a sidequest.

Any suggestions? (Im happy not waiting for the remaster because I still feel like Im figuring everything out at this point)