My advice to my younger self would be to say yes more and get all the experience possible. I was afraid to go beyond my comfort zone and that meant I didn't utilise all possible opportunities. I would advise people new to the industry to say yes to learning about every aspect of the business - from the back of house and work their way to the floor and eventually to managerial positions.
This would allow them to have a more in-depth knowledge about the running of the business from the ground up, which would help with achieving success. Furthermore, I would travel more, take more internships, do more unpaid jobs, and most especially I would get a mentor. A career mentor would help guide you on how to get success - your mentor may be someone you know personally or someone who's career progression you follow.
I would read more industry related articles, as well as joining industry-focused organisations to network ( which is also key) and expand my knowledge. Finally, I would be bold, be more assertive and of course start as soon as possible.