I'm Level 4. Only really played over the weekend but done everything in White Orchard other than played a game of Gwent. Just travelled to Vizima (I think).
Haven't really struggled too much - with the more powerful enemies it's simply a case of going in, using Quen a lot, few strikes, then backing off/rolling/dodge and repeat process. Took out the level 7 wraith outside the cemetery quite easily using this tactic, and then inside the crypt too. One of the most difficult battles was at a Place of Power fighting a bear. Oh and the Noonwraith (Devil o the Well) as I only used the Spectre Oil once, didn't use any traps or any bombs (those are her 3 weaknesses). So that took a while!
I've also got both the Viper steel sword and the Viper silver sword, crafted from diagrams. Had to buy some Emerald Dust for one of them and that wasn't cheap, but got lucky with the other as a wraith dropped some
I've got 5/5 quick attack, 1/1 Sun and Stars perk (health regenerates out of combat), 2/3 Axii and 2/3 Quen.
I also have no idea what to do with the Griffin Mutagen.
I think White Orchard is basically to get you up and running, so not many location pins on the map. The next area is huge in comparison and the map is literally filled with things to do.
Been excellent so far.