Reading all these replies is what I love about djing.
I agree with all the points and would often offer the same advice. I used to deliver djing workshops and had said most of the things mentioned above.
But
As I read through I’m thinking great advice but that’s not how I do it and that’s why djing is great. It’s an individual thing and one bit of advice I’d give that ive followed for over 25 years is be you because there’s a million of everybody else. Do what works for you, experiment and be confident in doing so. Also every gig is different so one set of rules that worked in one gig may not work next time. Be ready to be flexible.
Again this may be totally different for someone else and that’s fine.
One thing I always loved was being part of a collective or dj crew. We had few of those over the years and would play together on 4 turntables and 2 mixers. Great way to combine styles and music tastes. These were some of my fav gigs. Older now though and no time to meet up and don’t want to be saying I’ll bring my ‘crew’ as my kids may slap me 
As for practice in 25 yrs I still don’t have 2 tunes know mix perfect never mind practising entire sets. I did use to practice constantly but it was just djing, grabbing tracks mixing them. Mastering the mixer and turntable skills. May sound cocky but i never felt the need to practice a set as i feel i can just grab my music and mix it. Still today every gig is live and in the moment, I plan a few 100 tracks to bring then flick through and pick the next track and how I feel in that moment. Got to be ready to change direction at any moment, build upon what’s working and change what’s not. Actually was one time i practiced a set and that was when i stupidly entered the dmcs to make up numbers, i didnt win lol
Again though thats what works for me and everyone is different. When i was part of a team few guys used to practice routines, juggles and blends constantly and always perform them out exactly how they practiced them. I never had the patience and lacked their pinpoint technical skills. Thats why we worked great together, covering more styles and techniques.
When i took workshops we had DJs with many different goals and their paths would differ, some wanted to just play music they loved, some wanted to expand from production, others wanted to be a popular dj and seen it as a job and others just the idea of being a dj.
Answering your question where can i take it? I would say just enjoy it and let it take you wherever it does. Don’t over think, keep playing getting better, give your friend those sets and update them as you get better. Put mixes out there, stick some up here in this post? I know being older you have less time and energy to be putting gigs on, bringing mates and starting a vibe but thats what i loved about DJing when i started though i was obesssed with music and it was everything. I’m 45 now and couldn’t be arsed so only dj at gigs that involve me doing nothing but turning and playing music i like 
Lastly good luck and just keep enjoying it