I don't want to sound rude, but maybe if you have to ask this question you shouldn't be in marketing.

With that said, here are some tips:
1. Know that in marketing, as an employee in a PR firm the pace is very accelerated, you get few shots at making great impressions and you must take huge risks at each one. There is a high turnover in employees in marketing because of this fast pace high demand...
2. Try doing consulting work, I personally help small businesses evaluate their current offerings to the market, find the right product market fit and create strategies to pitch their adjusted value props to the market.
3. learn about blue ocean strategy if you haven't.
4. Pick one marketing approach, print, digital, animation, strategy, analysis, financial, SaaS, PR, sales marketing, coaching, regional sales management, there are many ways to implement "marketing" with clients.
5. Don't see growth as a corporate ladder.. in marketing that's almost non-existent.
Attend meetups, brownbags, etc where you can network and explore more real life approaches to marketing and meet people for possible future opportunities.

If you have a more direct question feel free to contact me, I have an MBA, sold several startups and have run my own marketing and consultancy team for about 8 years, currently serving as a strategic account manager for several companies.