It depends on two things: you and the site builder.

First, I would recommend that you start reading about SEO. It's a tough game but you don't have to be a specialist in order to play it right.

As for site builders, make sure you pick one that allows you to customize all of the SEO-related parameters in your site (alt for pictures, titles, etc.). If it's a good site builder, there shouldn't be a reason for your site not to be promoted properly.

I know that there are some site builders out there that can match your request. For my website I use exai.com and it seems to me that they're doing a good job.