1. you should go towards niches that are costly through Google Adwords. There are tools that tell you this like SpyFu.com. Something like Attorneys, Lawyers, Doctors, Insurance, and other types of service businesses, maybe like plumbers or home improvement types of projects (flooring, roofing, etc.)
2. Post original content. as much per day as possible. I would consider posting 30-50 times per day unique posts to the site if you want to get a lot of traffic. I would also launch a pop-up on the site to ask for their email address in exchange for a valuable list of secrets of some type, like how to save money on getting home improvement projects done for instance.
3. Wordpress for sure. Make sure you have a clean, mobile optimized theme. Make sure to add plugins like popups, sharing links, and maybe a forum if you plan to moderate it, that way you can have users generate content for you which there is nothing better than this as long as it's all good content. Most people spend too much time messing around with their website, when instead they should be posting as much unique, fresh content as possible. You can also hire people to write for you and/or pay college students to write content. The cheaper the better as long as they can write decently. You may have to give them the topics.
4. You can join affiliate programs. You ca become a merchant yourself and sell products through your website or blog, by using Shopify.com which is a great platform to sell on. You can find vendors to sell their products, in which case the content on the site would match those products. With Shopify, you can still create the blog with Wordpress and add Buy it Now buttons on your blog from Shopify! Cool stuff! I hope this helps. This is very accurate strategy, if you don't follow this you will not achieve those traffic levels. I have been doing this for 20 years. Let me know if you have any questions.
Thank you
Evan