Welcome to bhw,
@Svgs.
Got any advice you wish you had when you were new?
Make sure to triple check the rule book here.
As for business/marketing advice I would say pick one thing and focus on it for a long long time.
Try and avoid shiny object syndrome:

Imagine a friend says dude there's so much money in drop shipping, so you say awesome I'll learn it.
You see all these gurus making seemingly millions easily.
That's stage one.
You build a Shopify store and ah now you gotta look for products etc.
Time elapses and you realise it's actually way harder than you thought.
So now you're at stage two.
Now you say ahhh screw this drop shipping thing.
Drop shipping is dead

.
Then another friend comes along and says dude you gotta check this eBay flipping thing out.
So you say awesome I'll learn it.
Now you're back at stage one
Rinse and repeat for years.
Eventually you become the guy who says SEO is dead, drop ship is dead, eBay is dead etc.
And you just repeat the valley of despair ad infinitum.
Learned this from Alex Hormozi and it hit me because I realised that's exactly what I've been doing.