Any advice for a new, older player?

Sindiris

On and off casual play, but I want to get more competitive. I'd be in Masters division. Very intimidated about it all.

Any products that are best to shoot for?

Best way to practice?

Any other advice you think is helpful?

Octowen

Your local leagues are probably the best way for you to get some semi-competitive practice, as are League Cups and League Challenges.

Event locator link: https://events.pokemon.com/en-us/events

Event explainer link: https://www.pokemon.com/us/play-pokemon/about