If you connect a portable generator to a mobile home you must be sure that the house is not connected to the utility company line at the same time. In a mobile home where the power is normally supplied by plugging the house cord into the plug on the electrical pedestal this can be accomplished by just unplugging the cord.
If the house is hardwired into the power there needs to be a double pole double throw (DPDT) transfer switch installed. The diagram shows in general how this is done. The purpose is to make sure there is no way electricity from the generator can ever travel away from the home over the utility company lines and pose a danger to utility company employees. Depending on your budget, you can also purchase automatic transfer switches. These will monitor utility power and safely switch to a backup supply if the utility power is absent.
When using a portable generator, DO NOT bring it into your home. Every year, there are several media reports of people who have died from carbon monoxide poisoning due to running a generator inside their home. If the weather outdoors is such that the generator may suffer damage from operating outside, either don’t use it or make some sort of cover for it. If you live in an area where this is likely to be an issue, you might consider constructing a generator shelter before the weather is bad enough to need one.