How to use async/await in typescript

I want to call a http.get method off my ThemeService and make it as "synchronous" as possible so that it continuous after it gets Theme from the call. I searched on how to do this and stumbled across async and await. I tried to implement this but it didn't quite work. I put some console.log() in the code so i can see what is and what isn't executed. The "IN ASYNC FUNCTION" and "AFTER ASYNC" are executed but not the ones after/in my call on ThemeService.

Because i am new to the async/await functions in typescript i don't know if what I have written is badly or if what i'm trying to do is possible or not.

ngOnInit():void{
    let id = +this.routeParams.get('themeId');
    async function getTheme(){
        console.log("IN ASYNC FUNCTION");
        var val =  await this.themeService.getTheme(id).subscribe((theme:Theme)=> {
            this.theme = theme;
            console.log("IN AWAIT FUNCTION")
        });
        console.log("AFTER AWAIT");
        return val;
    }

    getTheme();
    console.log("AFTER ASYNC");
}