If you're not technically inclined at all, register your domain wherever you set up your hosting. Otherwise, you can save a few dollars by choosing a lower-cost provider. This is not a big deal for one or two sites, but it can be for 10 or 20. GoDaddy is a good option because it offers great domain management tools and at a low cost annually. One of the least expensive and reputable in the market is 1&1. Prices start at the low end of the spectrum for the first year with increases, sometimes significant for each subsequent year, depending on what plan you choose.
If you're interested in online marketing, setup email software and create a lead magnet that you can use in your sales funnel. Then, build up that list. It's often said that you can expect to earn about $1 per subscriber per month. If you have a list of 10,000 subscribers, that means you can earn roughly around $10,000 per month. You will need to deliver value and not pitch them on every email, but it is a very achievable goal in a short period.