Google Adwords or Google Ads is not free for setting up campaigns and running paid ads however to view the interface or dashboard you need to just signup with google which is free. After signing up google dashboard appears. If you want to promote your products or for an event it is always paid on any platforms not just google to reach more people. But what I feel Google is one of the best platform and its worth it to advertise. You can do Search ads, Display Ads, Youtube Ads on google
BETTER THAN FACEBOOK ADS
Compared to Facebook you show ads to people who may or may not want to purchase your product but google shows ad to audience who likely want to buy product. For example if running a search ad on google for shoes. A person is likely to buy product when he search that product on google and clicks your paid ad and if gets converted is purchase. So, the person is a potential customer because he comes to view your ad. But what is one of the most important thing in google ads are the keywords. It should be precise and keeping a regular check on that(adding worth it keywords to campaign and removing keywords not worth it by doing it negative).
It takes around 15 or 20 days to optimise google ads after that it starts giving results. However but when need to have patience. Google will give results for amount being paid. Running display ads is also a good option you need to create two images of respective sizes for your product, services or event and google shows this ad on different websites, apps automatically which gives conversion.
Trying promotional youtube ads is also a good option like skippable ads or non-skippable ads on youtube brings conversion by uploading on your youtube channel and then adding link on google. Youtube is a great platform and ads is highly convertible. As you can see ads of Netflix, Semrush, unacademy usually do youtube ads where communication is better to audience
Smart campaigns is a great option to where ads will be shown to potential customers automatically in targeted or geographical areas.
Though google ads are not free but spending on it is definitely effective and profitable.