I find it hard to train dungeoneering for an extended amount of time so I figured doing it during the bonus exp weekend would be a smart move. Are you able to get bonus exp doing dungeoneering and how does it calculate the bonus exp if so? I would like to solo at least till 70 so any calculations on time taken would be helpful

It's double your exp, but you still only receive 10:1 exp:tokens. Exp rates at a low level change a lot and also depend on how fast you're able to actually finish a dungeon. I'd guess 2-3 hours depending on how fast you're able to go through dungeons yourself.

Based on past weekends:

The final xp value, as in after its done deaths etc etc., gets multiplied by your current multiplier.

But tokens you only get on the ORIGINAL xp, not on the bonus.