I want to build a basement, but i want to know if it is safe to construct that thing with fooder or lumber, will it be destroyed if a storm hits? (this sounds really stupid because basements are kinda like under the earth but whatever
Your best bet is to build the basement out of gold lumber or stone. Like Muffy Princess Moon stated, it doesn't matter whether it's underground or not, the same rules still apply. The basements will still be susceptible to collapsing during/after a storm if made from fodder or lumber, so it's not very advised.
However, if you can only choose between lumber and grass, choose lumber since it's a sturdier material. Never choose grass, since that'll never survive a rainy day let alone a storm.