As an Indian passport holder planning a trip to Slovenia, you will indeed require a visa to enter, with several options like the tourist or business visa available depending on your purpose of travel, and you can typically stay for up to 90 days within a 180-day period. The Schengen visa fee for adults is currently around €80, a significant factor to budget for your plans. Given Slovenia's commitment to the Schengen Area, planning your application at least 6 weeks before your intended departure is highly advisable, especially if you're considering visiting during the popular summer months from June to August.