Why did the converter fail? Running rich? Engine burning oil? Just age/miles? If there is an underlying condition, address that as well or first. It may also be suggested to change oxygen sensors at the same time. This is UNDER most cars so access to the interior shouldn’t be required.
It isn’t ideal to drive this way but shouldn’t kill you or the car. I assume there is a check engine light. If solid, fine. If FLASHING you risk additional damage by driving this. A flashing engine light should be addressed IMMEDIATELY.
As with any car, don’t let it run in an enclosed space. Try to keep moving and turn off the engine if parked for any length of time. You should be fine. The fumes may just be nasty but you might have an exhaust leak as well. That is simple and low-cost to fix compared to anything else needed.