Did you take up an apprenticeship/internship at a marketing agency? or did you experiment with your own money
I used my own money.... it was 2008 or 2009 when I first delved into Adwords (my first ever PPC network) and back then it was such an easy way to make money. I remember that I've deposited $80 into my Adwords account, set up a campaign targeting 3-4 keywords with high search volume (but still pretty targeted), then added my affiliate link for a Clickbank product (and yes, at that time Google did allow affiliate links), then refreshed the campaign for a few (20-30??) minutes, noticed some clicks and impressions but no sales yet, then I went to sleep as this campaign had been set up around 2 AM.... And when I woke up (around 9 or 10 in the morning) and checked my CB account I noticed that I've made 3 sales totalling $115.... or $116 worth of commissions.... which, unfortunately, I was never able to withdraw until few months later due to some country and account freshness limitations, I don't remember the whole story but it's been a PITA to get that money out of CB 16 years ago...
Anyway, after this success I made plans to invest all of this money back into Adwords and I also bought an ebook on how to make money with Adwords that had just been released few weeks earlier by 1 of the biggest SEO guys of that time (or at least that I know of, there might have been others that have been bigger than him), named Brad Callen, whose SEO tools and PLR products were absolutely top notch quality....
Anyway, I purchased that ebook (I think I've paid $97 for it) with money from my own pocket and went on to study it in detail, with the thought in the back of my mind that I would put this knowledge to good use when I got that $115 out of CB so I can deposit it back into Adwords.
But what would you know! Not even 1 month later after I have wasted my money on that $97 ebook Google have made DRASTIC changes to their Adwords system (I guess they didn't like it that too many people were making easy money with them?) some of which the biggest ones (back then) have been no more affiliate links allowed (this had devastated me back then, and I think it's the main reason for which I purchased my first domain name ever and looked for other ways to making money online), and I think there was also a $100 minimum deposit limit put on new Adwords accounts, of which - for some reason - mine was included into.
But anyway, that's when and how I've learned PPC. But if you manage to master Adwords (well, Google Ads as it's now called) I think you'll do fine in every other PPC network because the principles are absolutely the same across all networks. Just the type of scumbaggery and rip-off, and the terminology might differ, but the principles are the same, like I said: create ad, choose keywords, attach link, profit (if you know how to convert and close the sale)....
So there isn't much to learn in terms of actual knowledge. The real tricks are to keep optimizing the campaigns like a lunatic (or a robot, it's the same thing) by staying glued to your screen 24/7 to analyze every impression, every click, every mouse scroll, every step of the funnel, etc.... and to also weed out non-converting keywords that eat through your budget, those are actually one of the most important deciding factors for your good or bad ROI...
Anyway, PPC had become a rich man's game, so if you don't have at least $200-300 to waste upfront (in order to "warm up" the campaign supposedly, which is nothing more than the big corporations stealing this money from you, nothing else), I recommend you don't play this game as you will almost guaranteed turn a loss on your 1st campaign, no matter what you promote and how good your landing page is. Google will simply refuse to send you converting traffic, I think they reserve this traffic only for those with big budgets, which is probably why they've introduced the "campaign warn-up" excuse (to see who has lots of money to burn)
