how to know strike price from startup just joined if not in written contract?

i just started wkg, but noticed that the strike price is not indicated, ex: $.05 or $.20/share, etc.while i have certain #of shares. what's the best way to know by asking, what are some key questions i can asked so i'm not tricked into a false price? from research, employees get 25% discount of what investors' valued shares - is that normal, or case dependent? is this normal not to include this info in contract or depnds on board of directors' mtg then the price is decided? but isn't that already done before the job's offered? thanks!