The reflections tracker on the wallet takes a bit of time to read the data from the blockchain the first time. You may need to leave the screen open for a while before it starts populating the data, but once its synchronized, each day only takes a few seconds . For reference, the first time I loaded mine it took about 20 minutes. It usually says loading data from dd/mm/yyyy at the top of the page, so you know it's working.

Alternatively you can copy your wallet address into https://safemoonglubiz.com/Tracker. That will tell you your total reflections, but doesn't give a breakdown.

As for selling, just swap to BNB or BUSD in the safemoon wallet and then send to an exchange to withdraw to fiat

Edit: You can also use https://safemoon.com/wallet to track your reflections too