I'm starting my first job in a cafe this weekend. I'm pretty nervous, I have no proper work experience yet (I'm nearly 16) and if anyone has any advice, in particular for working at a cafe as a waiter/cleaner it'd be greatly appreciated!
Take every bit of advice with a grain of salt.
Each work environment is different.
A lot of service industries tend to have drama associated with them. You'll get to hear what waitresses really think about a customer, what they think about the intelligence and capabilities of the cooks, whether or not it was worth it for them to come into work that day, etc.
Again, this does depend upon where you work, but I've noticed a lot more drama when I've worked in service. You're not going to be able to avoid all of it - just try not to let it consume you.
This may sound contrary to what you're going to hear from a lot of people, but learn to sit back and enjoy the job. You're not going to work your way to riches in the service industry and it's not like you're going to get a medal that your next employer is going to jump up and down about.
If your job is to clean tables, take pride in being methodical in your cleaning of the table and in being proficient at it - but don't kill yourself for praise. Also, there tend to be a lot of times where you get 'shafted' with a duty that will last for some time while others leave or are doing other things. Try not to set too many schedule-oriented goals around work where you get upset because you're not going to get out of the place nearly as early as you thought you were.
Don't be afraid to socialize with people when it is appropriate. You're going to be spending a considerable amount of time with these people and working to become a part of their team. You don't have to become their bestest-best friend and hang out with them outside of work, but you can send the wrong message if you just "clock in, do your job, and clock out."
You aren't performing your job in a vacuum. There are many other people involved in the process who are invested in doing something that makes your job possible and/or meaningful. Get to know them.
And in the service industry, you'll have plenty of times where you're waiting on customers. Two or three hours of little to nothing and then a bus will pull up and everyone shits their pants. It's better to get to know them when they don't have shit in their pants.