SENTINEL1A_1W_SLC_ISSV poducts free downloads

Hello Mr ABraun, I am From West Borneo/Kalimantan Indonesia, I am working on Wildfire Classification. What is the best Sentinel I can use? How can I get Sentinel Image? And If I want to use Sentinel with SAR, Where is the website I can download the data? Is there any program from ESA that I can using it for processing the data? Thank You

Regard
Pramulya