Questions related to basic google ads setup

Guys,

I have an health app which is basically based on healing with music and yoga and some other practices. The app is currently under development but I wanna drive traffic towards the website and I am completely noob for Google Ads. My target audience is US people with mental or any health issue. So what budget and CPC should I set to rank on the first page and which keywords should I use? Or what should I do exactly? Is the traffic source correct to get this kind of audience or what else ...