I've worked in this industry for over 15 years now.
I've seen all ages of guys buy boards and pick up skating.
To be frank, what you want to accomplish is......a pipe dream.
To get a legitimate skateboard it'll be more than $100- think $140 (i'm not talking out the box pre built, I'm talking custom from the wheels up).
Public skate parks are usually free - you can ride without gear (helmet usually) however prepare to be fined by a park ranger if they roll up on the park or bail out with the younger kids
Downside to public parks, they might be littered, shady people, drug deals, locals only, not maintained.
Private parks cost money, average is about $10 a day (you can get memberships), BUT you need to buy or rent a helmet and probably kneepads.
Upside is the park is clean, no shady people, well maintained, bigger area to skate, more shit to do.
I skated everyday after work for years and never got good as these pros, some guys just have natural talent.
You'll find out soon enough if you're cut up for it.
NOTE: The older you get, the harder the falls are, skate at your own risk, if you work with your hands (construction, office, etc) be prepared to have fucked up palms/wrists/hands from falling (unless you want to wear those gay ass wrist guards).
I skated everyday after work for years and never got good as these pros, some guys just have natural talent.
3 years isn't shit in the skate world.
Out of all the kids we sponsored - I'd say over 30 kids over the years:
-10 became "flow" - this means they aren't paid but they are sponsored by skate companies and get free shit/allowance monthly.
-5 became "am" - aka amateur, this means they got their gear and contests fees paid for, they MIGHT get a monthly allowance.
-3 became Pro - these guys are the heavy hitters, the ones that kill it in contests, get connects and major sponsors (think nike/addidas/etc)
-Those 3 guys get paid by their sponsors, they get checks from the gear under their names, if they win contests they make bank.
Problem some of these guys pissed their money away, started fucking up and not going into contests - there's 1 guy of those 3 pros who made it onto TV and is apart a skate series on Vice.
As for your GoPro it isn't $150 at least the full version isn't, it's about $400-500 new. I guess you can buy those little cubes also.
You're forgetting one major thing
EDITING.
This is one of the hugest factors:
-Finding spots to film/shoot.
-Finding the right guy to film/shoot for you.
-Finding the right guy to edit film/pics for you.
Barcelona has a thriving skate community that has grown in the last decade.
The editing these pros get is fantastic.
Like Cowboy said, do shit you have a passion for, not "just" to impress girl.
As for said girls:
You aren't going to find dime pieces in that skate scene, unless they're groupies following some dudes like Ryan Sheckler or Paul Rodriguez.
The girls that come into skate dress like tom boys and dress all hessian/grungy. (You'll have better luck finding "skategirls" at a punk show.)
We had a girl I'd consider a 7 who worked for us....turns out she's a lipstick lesbian !
Sadly I rarely skate anymore, I'd rather snowboard or ride Harley's)
My advice to you ?
Forget the skateboarding, more girls are into snowboarding than skateboarding.
We sold both skate and snow, there were more girls consistently getting snowboards than skateboards.
There's plenty of snow bunnies who are down, smoke weed, and sleep around. Only downside is it's seasonal (unless you're a liftie on the mountain).