Hello there if you want to cast a protection spell there are many protection spells here on the site. Just becareful and read through them. Some of them can be fake. but most of them can work too.
I sometimes like to use salt for protection put it in the corners or windows of my home and also place some outside of my home. Salt is a protection item that repels negative energny and spirits and keeps all harm away from you. You can also cast a protection spell aslo. You can either create your own spells if you know how to. Or you can use a spell someone else has made. Personally i would create my own becaue it gives it your own special kind of energy and makes it stronger that way.
There are also many items you can use to place in your home to protect your sisters or family or who ever want to protect. You can use charms or stones or even crystals. Charge them with your energy. A Clear Quartz crystal is used for healing, protection. You can charge them and wear tthem or place them in your home for protection. Even incense can be use for protection. Here is a list of incenses you can use. There are many ways for protection.
Do you know how to cast a spell properly? If so just look around or maybe try to create your own. Hope this helps