I usually put my keywords in the All in One SEO pack section where it says "keywords."
I also enter the keyword in the title and first paragraph. Many times I just enter a single keyword. Not really sure if that's right though. I'm still learning this whole SEO thing. Lol.

I always recommend that you leave the All-In-One SEO fields blank on a page and post basis, as does Kyle and Carson. If you listen to Kyle's voiceover around 6:50 in this video https://my.wealthyaffiliate.com/training/getting-your-website-seo-ready you'll hear him say: "... and we only have to update the home page title and description fields, all the other posts and pages are going to be taken care of that we create, because this tool (All-in-One SEO) actually automates the rest of the pages that you create, it will create the title and description for you automatically, we only have to do this once and then we're never going to have to revisit this tool again...". The fields are occasionally useful, for example if you had a page or post that simple had a video or image on it then by all means write a description as there's no text for a search engine to create the most relevant summary from to display in the search results. I've never filled these fields in on a page and post basis myself and it's certainly never done me any harm! :) Rich.