If you're playing micro/low stakes don't bother paying for a course save your money. There is so much info and poker knowledge available today for FREE that it's way more then enough to beat micro/low stakes. This forum has a 30 day course. Also check youtube and twitch for plenty of free stuff. I'm still playing a somewhat TAG style built around 20 years of experience and info/knowledge from all the best 20 year old books with a few changes to exploit my player pool. Still winning in 2023.
You wanna spend money buy a HUD even if the site you play doesn't allow them. A HUD is great tool for also helping you study and review hands. I prefer Poker tracker 4. There are a number of different HUD's just run a Google search and many offer free trials for so many days before you need to pay. I'd test them all and choose the one you prefer.
In my opinion here's the main things to work on to beat micro/low stakes: patience,
bankroll management and mental toughness/tilt control. You can be the best player in the world by far and still lose long term because of those few things.
Do this forums 30 day course if you haven't(even though I didn't lol). Then I'd start with preflop charts/ranges. Learn a Tight Aggressive style(TAG) starting with the ranges from every position and memorize them. Next focus on SB and BB ranges and defending ranges from the BB. That's plenty for now.
Cheers