The manual options are ancient - like a sickle, or a scythe or clip by hand with garden shears bent down on your knees for hours. But fuck all that, you’ll want an electric trimmer for edges.
Two things: I’ve edged my grass with pavers fir the most part, and for the small bits that don’t have that, long handled edging shears you can use while standing.
The other bit is that I don’t have a rolling lawn that needs a riding mower; my grass is interspersed with local plants/shrubs/trees. Only takes 10 minutes to fully trim the grass bit during the season where it’s growing.