Well, there's no rush at your age.
Be open-minded, willing to ask questions and willing to learn. You'll find your own style of officiating at some point.
If you want to improve your chances of going up the ladder though then my advice once you've completed your initial five and are level 7 (or whatever) would be;
1. Be available - The more time you have to officiate, the better. If you're one of the lucky ones that can be available all the time, your fixture secretary is going to love you. Don't over do it though, some people do five games per week or something crazy like that. Be aware of mental fatigue if you have a fixture over-load.
2. Do your paperwork (Cautions, sending offs etc.) - if in doubt on these, ask your RA for help, there's usually always a point of contact who has a wealth of information to help you out with. I still send off e-mails once in a while to double-check caution codes even now!
But they're there to help you find your feet anyway, so ask questions! They'll help with most things, misconduct white paper reports for example.
3. Have a fitness routine outside of football - This was stressed to me by assessors when I was around your age. The mantra being 'Don't referee to get fit, get fit to referee.' You'll need a decent level of fitness to get up the ladder anyway. If you're at all serious about it, start thinking now about what lifestyle changes you'll need to make; Cut out the alcohol for example, be more considerate about your diet, be aware of the mentality side of things too; Get a good night's sleep before a match, try not to make mistakes such as going on a stag do the night before a match etc.
4. Get involved with your Referee's Society - Get to know people from all levels and abilities. You'll be partnering up with some of them in the future anyway, so you'll learn what to do and what not to do from them on the field as well. In the meantime, at meetings you'll get to hear of incidents that occur that need discussion. It'll also cover local issues. At mine the league and fixture secretaries are in regular attendance and will keep everyone up to date with issues on their side such as league re-structuring or other political issues.
5. Never stop learning - I've fallen into this trap myself, but I've seen it happen with a lot of referees. They do well, they get settled, they get some bad advice somewhere along the way, they stop learning and become unwilling to be flexible or change something. You may not even realise you're doing this. Always take time to self-reflect - be your harshest critic. If you're coming away from matches with the impression you've had a great game with little to improve on consistently, then you'd better be hoping that an assessor is agreeing with you! Even if you have a 9.9/10 match, find something that you didn't do well and think about how to fix it. (This isn't to say you should get into a spiral of self-defeatism though, that's not what you're after. You're after self-learning and criticism, not 'oh woe is me, I'm an awful referee!' etc.)
6. Regarding above: Advice comes from anywhere - Try not to be dismissive of it. Some of the best advice I've had has been from players or managers believe it or not. Savvy players know the tricks of the trade, they know how to disguise fouls - If you're lucky, a player or manager will point this out to you in a more helpful way than usual. Of course, you have to be careful with advice from players/managers - there's a lot that you will have to filter out. But there's always something you can pick up from anywhere. One of the best bits of advice I had was from a disabled child when I was officiating in a disability tournament for charity - In fact, that incident that day was how I figured out I fell into the trap of point number 5.
7. Have fun - The most important rule for me. You'll encounter a lot of obstacles over the years; abuse, injuries, politics, external factors. These can be draining. It should never feel like you're stepping out there because you have to. You should be out there, because you want to be there, because you're enjoying it, warts and all. Take the time to enjoy yourself, take the time to celebrate your successes, minor or major.
8 Track your progress - This is completely irrelevant advice actually for promotion. But, as you're a young referee, here's something I wished I did when I was your age. Download a tracker spreadsheet, like the one on the resources page here. Start logging all the games you play in. I have no idea how many games I've done over the years, and that's probably one of my biggest regrets so far, logging everything so late in my career. It gives you something to look back on and to see how far you've come.
I think that's all I can think of right now. Hope you have a fun career.
