I'll use a fictional hand as an example. We're playing 6max NLHE, lets say 100nl and have no reads on any of the players, maybe 10 hands of stats but that's it. We've not done much, raised the odd good hand, folded for the most part but we've only been there 10 hands so not anything real to go on.
We get

in the bb.
BTN raises to $4, SB calls
The 10 hands we have on the BTN are 20/10/-, and the SB is 40/0/-
Now with good reads on the BTN being a standard TAG I'd 3bet this a fair amount and call sometimes, very rarely folding if I have him as a 20/17/3 type.
With no (or very limited even) reads, how are we proceeding?
Is it really weak to just be folding this early in the session?
Should we if anything be MORE aggressive and 3bet more in this spot?