Good question hard to answer.
I'll try my best.
Google indexing will also push you to other search engines to get seen free.
But bad side it all depends on your SEO skills.
Adwords is google but paid traffic, can start straight away and get traffic to a website/landing page.
But the bad part can cost a lot of money trying to get correct keywords to make money.
The problem with adwords is you need a really good amount of spare cash to do split testing, split testing is when testing keywords that get traffic but also convert with deals you added to the website.
If you go the free SEO traffic route or the paid adwords traffic route they all need knowledge or you can be wasting time and effort with an online business.
Gd luck
Ps.
You can find tutorials on this forum and udemy and YouTube, I strongly suggest reading before losing time and money.
Adwords is traffic, but to get correct traffic to convert to money take design skill and good keywords.
A lot of people think adwords is just keywords and earn, that not true, a keyword is your bread and butter, so doing deep keyword research will help to get the correct keywords needed.
You need online tools.
I suggest.
Google trends <<<<< FREE
Internet in general on your niche <<<<< FREE
ahref <<<<< if can afford it to see what the competition doing.
there free stuff as well that might help, please look around...