smoke coming from engine

[20Bonneville00]

So my ssei bonne has been sputtering at the start and its been really rough at idle. i assume it is spark plugs so i got some ac delco replacements. i just ran it up onto ramps, popped the hood, and noticed white smoke coming from what looked like right above where the spark plugs are. i have no idea what this could be and i could really use some guidence. also a side note. the box of the new plugs says to "gap accordingly" or something like that but the plugs don't seem to be adjustable at all??

[nos4blood70]

The smoke is probably oil burning from bad valvecover gaskets.

You need a gapping tool to adjust gap on plugs.