You should be sure to look through the Darkroom portraits and temporary darkroom threads at the top of this forum.
Some safelights are just bulbs with the right glass or coatings, while others are regular bulbs behind filters. There are also LEDs that work as safelights, and more exotic light sources that emit light that is safe.
For B&W printing, tiny bits of dim light can leak in, but for film, not so much.
Remember that you will need a source of electricity, and you will also need white light too.
You might want to do a dimensioned sketch, indicating where electrical and water sources are, and post it here.