Social media is buns, yeah. I DETEST doing it for myself. If you did still want to take advantage of it, you can do it without even opening the apps. Batch create your content in Canva or whatever, then sign up to something like Postoplan (I have the lifetime deal, works gr8), schedule it, forget it until next month.
For SEO, I’ve always split it up into two categories - technical and not-technical, lol. The first one is your on-page metrics that Google pay attention to, like loading times, domain quality/age, stuff like that. The rest is what you’re talking about, with ‘keyword stuffing’ (although that’s not considered great to do). You can figure out your keywords in a bunch of ways, Neil Patel’s UberSuggest is free and great, and Google has their own tools that I don’t personally love all that much.
If your website is solely your poetry, and no opinion posts, no pages about you, nothing else, then yeah you’re a bit screwed with most SEO, except for page headers, description and backlinks. Backlinks are just links from other places, say a magazine mentions you and links to your website. The header is the < title > and < h1 > < h2 > so on of your web page. The description is specifically the information Google reads and displays in the search results, which you can and should manually edit for each page/post.
That said, you probably should be organising your blog somehow, and that can help you with your SEO. Think ‘Poems about X’ or whatever, but do some research because I haven’t audited your site or niche and can’t give any specific tips :’) You can then link those pages together, do some on-page SEO, and also organise your site so people who want to specifically read about a certain theme can do so easily.
As for non-SEO and non-SMM ideas, you could always turn your blog into a community of sorts. A forum, Discord, or other meeting-place-type-thing where people can get together and share their own poetry, or have VIP access to your poems before anyone else. If your poetry tackles certain themes, you could reach out to events or orgs that are about those themed (for instance, if you write about living with migraines, you could reach out to a migraine charity to see if they would like to share your work or interview you).
If you have money and/or time to burn, podcasts seem to be the ‘in thing’ right now, but you would need equipment to get started. Adobe’s Podcast tool is actually really great, if you don’t have an amazing mic.