If you don't understand the deal in front of you then don't sign.
If you don't understand how options work then don't sign.
If the hiring team is pressuring into an option plan then don't sign.
Get paid what you are worth. Don't let anyone offset your market value with options (eg - a lottery ticket). Demand the market salary AND the options.
Alternatively, forego the options and take more cash. Take more vacation days. Take something that has demonstrable value.
Fact. Most startups will fail, making your options worth zero.
Fact. Most funding rounds will dilute you.
Fact. You still need the cash on hand to exercise (eg - convert options to shares) the options.
Fact. In some cases you will need to buy into an option plan.
Fact. You create a tax hassle for yourself with little upside in many cases.
Go work in someones else's startup to learn, have fun, grow network, and build experience. Don't join if you hope to make it rich.