I do not have a main breaker in my breaker box
You likely have a &quot;split-bus&quot; panel. The NEC allowed no more than 6 switches to disconnect all power from a building. The top of the panel has space for not more than 6 two-pole breakers, one of which fed the lower section of the panel. Was legal.
Bigger issues are brand, age, and capacity to add circuits.
First brands. Zinsco and Federal Pacific have history of defects, you should consider replacing ASAP.
Second, the 2nd law of thermal dynamics, everything goes from order to disorder, things wear out. Your panel is aging to the point that a critical failure could happen at any time.
Third, many split bus services were only 100A, it sounds like you have some capacity (if you described all the significant breakers accurately), but adding a EVSE or air conditioner may be out of the question.
Also it is a bit odd to have a range on a 2p30 breaker, may be inadequate supply to Code standards, but not likely to cause any damage, just limited power available to be used at the range.