Many posts on this site by new owners flying indoors and damaging their drone and home. Much better to learn to fly in a wide open field. Lots more electrical and magnetic interference indoors too. If you have access to a giant indoor room like a gymnasium that might work however.
Most pilots get tired of gesture mode pretty quickly. It doesn't work reliably and is very limited compared to remote control. Using gesture mode indoors would almost certainly result in a ceiling strike.
When you're experienced enough to fly indoors best to use prop guards and Tripod Mode. Even then it's a bit risky.
Spark can't take off in a NFZ since last update. You can no longer call airport to get clearance either. This should change when LAANC system allows electronic clearance through the app.
Enjoy!