There are several ski hire shops in Les Gets and Morzine where you can hire (or buy) skis, boards, boots, and much more equipment. Most are very reputable and are proud of the service and quality of rental equipment that they provide.
A good boot-fitting service is critical to avoid discomfort during the holiday. Many people think that ski boots are supposed to hurt - they're not! If they are giving severe pain there is definitely something wrong. Sometimes the discomfort only emerges after a few hours on the slopes, and all reputable rental shops will re-fit or exchange the boots without question.
The same goes for skis. It's worth being honest about you're capability to avoid ending up with a pair more suited to a free-style expert!
The shop will ask you about your experience (beginner/ intermediate/ expert, or number of weeks skied) and any skiing preference (fast on-piste, turning, bumps, off-piste, etc.). You will also need to know your weight in kilos (for ski binding adjustment) so it's worth having that ready.
Most shops also now have ski/boarding helmets for children and adults alike. Not only does head protection make sense, it's worth remembering that many ski schools require children to have it.