The service industry may seem like starting at the bottom, but that means that there is room to go higher. We know that most companies promote from within. While executive or technical jobs recruit new employees by poaching, this is not a factor for more than 90% of the jobs.
So, come not only prepared to give a good day's effort but to show that you are the kind of person the company should promote. You really never really know, but regardless of the experience, you are getting experience and growing your skills. If you do not get the promotions that you deserve, your experience and skills give you leverage to move onto another job or the impetus to start your own business.
A weekly-paycheck not only pays the bills, but gives you time and insight of what to do next.