https://www.therippedbodicela.com/about

The Ripped Bodice is a brick and mortar bookshop in Brooklyn NYC. Never visited it myself, but they advertise specializing in romance novels of all sorts.

Hope that helps.

Definitely not my genre, but you could try The Rosie Project by Graeme Simsion? It's fairly comedic but I think checks all your boxes pretty well, including the last two (maybe not quite hate but definitely don't view each other as romantic prospects)

Well the anti-reccomendation would be to stay far away from the Outlander series. ;) It's a neat conceit, someone from the present day thrown back in time and falls in love with a Scottish highlander, but there's a ton of drama over her having been married in the present day, and the primary antagonist being her husbands ancestor who looks just like him and yadda yadda.

Mostly the love triangle thing is impossible to avoid because, dramatically speaking, that's a fulcrum point.

Hello Stranger by Katherine Center might be one that fits the criteria.