>>52673
>mushrooms growing from a dead tree.
Some good, most bad or inedible so as usual, if you don't know 'em, stay away.
>white and brown-ish
Could be similar to agaricus campestris or a macrolepiota. But just from that description I can't guess.
>do some research online and pick them up if they look good.
By touching a mushroom you don't get poisoned. You can pick one take it home and do a thorough research on it. You can discard it after.
Dig it out carefully and take the whole thing, don't cut it down. Because the shape of the stem can help, and for example the existence of volva (see here: >>40533) can help you exclude many species.
You can gather it into a plastic bag, but one that's made of some kind of cloth, cotton/linen/canvas, would be the best.