Should be accesible fast. But i would not recommend it for a totally fresh account. You would get wiped fast if you only have the starter character and no upgrades.

You need to have unlocked the 2nd main stage before any of the DLC stages become available. That's enough to get your foot in the door, though it is worth noting that quite a lot of the DLC content will require additional unlocks from the base game.

I've put about 11 hrs into the main game. ( which I know is nothing lol )

I'm often wondering if I'm playing the "right' way. Am I thinking to much? :P

Surviving and buying upgrades and unlocking stuff. I suggest looking at a guide like this one.
https://gtm.steamproxy.vip/sharedfiles/filedetails/?id=3221409140

引用自 Andrew R：

I've put about 11 hrs into the main game. ( which I know is nothing lol )

I'm often wondering if I'm playing the "right' way. Am I thinking to much? :P

As long as you're having fun, you can't really go wrong. No need to worry about guides until you start struggling to unlock stuff.

引用自 Andrew R：

I'm often wondering if I'm playing the "right' way. Am I thinking to much? :P

This is absolutely a game where the designer just gives you a bunch of options to play your way.

I have several options open to me; Stage 1, 2, 3, White Out ( Bonus ) and Castlevania.

What would you recommend? :)

From top to bottom. Castlevania is not something you should rush into.

If you have Inlaid Library opened, you should focus your time there, in general its considered MUCH easier than the initial stage Mad Forest.