Sit at the bar counter, not outside at a table
The bar counter is where Granada's free tapas culture works, and it is also where solo dining is entirely normal. Every local in their twenties and thirties eats standing at the bar, glass of wine in hand, working through a tapa, another round. There is no awkward dynamic of a solo table. Realejo's bars (Calle Pérgola, Plaza del Realejo, streets near the Torres Bermejas) are particularly relaxed. The staff know their regulars and a solo woman at the counter attracts no attention beyond a prompt to order.