If you're planning to promote affiliate programs as a long-term venture you will need a few tools to do it properly.
Here's what I use and recommend...
Hosting and domain registration
As a premium member of Wealthy Affiliate I get the best WordPress hosting I've personally used, secure, fast and with great customer service. Wealthy Affiliate also provides training on building a successful business and a great affiliate program which I actively promote.
WA provides premium members hosting for up to 50 domains all with the SSL included for a cost of $49 per month.
The WA domain registration includes EVERYTHING that all the other extra for. Yes a flat rate of $14.99 per year with ZERO UP-SELLS!
For those on a tight budget that just want to 'test' out the concept of affiliate marketing WA also offer a free membership level that includes basic training and 2 free websites with hosting (yourwebsiteidea.siterubix.com). This is great because unlike other 'free' website platforms there are no restrictions on posting affiliate links, and once you've validated your business idea you can move your site to your own domain name and hosting very easily (even if you have no tech skills whatsoever, and if you choose WA hosting it's 2 clicks of the mouse easy).
Lead Capture and List Building
I use Thrive Architect for all my content creation and lead capture needs. A WordPress plugin that will work with ANY WordPress theme and for me is invaluable and fun!
I also use an app called Designrr to turn web content into beautiful PDF lead magnets really fast.
Email Service Providers
I have used Aweber, GetResponse, and Active Campaign. They're all good and Active Campaign is the best at list segmentation, but getting started all offer introductory deals...
There are literally hundreds of other tools and services available (I own many of them), but the ones I've mentioned get used almost every day.
Also if money is tight you can build a list using Wealthy Affiliates free website and one of the email service providers, which is a very low cost way to start a business.