Hi Jessica
The first thing to do is to READ JoS. There is a lot of info to look at. I would suggest going to Satans Library and reading all of HP Maxine D's sermons. You will find it really informative. It will answer a lot of questions for you. And read the other HP's sermons too of course. I started with hers since she was the sites founder.
You will find on the JoS site the info on how to DEDICATE. You do this when you are ready. You DO NOT try to contact a Demon till after you are Dedicated. By the time you do all the work studying and educating yourself, your questions will be answered. But I will try to help in brief:
how do I begin to contact a demon what do I have to do? :
Dedicate.
will a demon protect me and a loved one?
Not just any Demon, no, but if you are DEDICATED, you get a GD

OH, sorry, that means a Guardian Demon.
How do I ask them to?
How does one ask a dear friend or family member anything? Nicely. Respectfully. And be willing to give in return. It's a two way street, as is any relationship.
what do I have to offer a demon in order to get his or her acceptance dose it have to be my soul?
This is a typical misunderstanding because of the enemy programming rammed into peoples heads. Satan's Demons aren't interested in your soul! Just in what will YOU do for Satan?
I only have white candles and no money to get the things I may need to summon a demon is there a way to summon without candles and other stuff?
How much do a few candles cost? Sheesh! There are several answers one could go into here...but first, you DON'T 'summon' a Demon. You ASK. And NOT till after you are Dedicated. Satan's demons do not take it kindly if someone Without (that would be YOU till you are Dedicated) tries 'summoning' them. It is not necessary for props though some things are very nice to have, out of RESPECT. You see, its a RELATIONSHIP. How would YOU feel if you knew someone who never offered or did the slightest thing for you, but wanted all sorts of things from you? You'd feel used, right? The Demons have feelings too
If you TRULY can't afford something, they are very understanding. You are getting way ahead of yourself, though. You need to start applying yourself and putting in your own effort, and the first thing is to STUDY here at JoS and in Satan's library. When the Demons see you are trying and putting something of your own in, they are more likely to be open to respond to you. If you just want something for nothing, don't hold your breath. But even after you Dedicate it could be some time before they choose to make contact. High Priestess Maxine D said it was an entire year after she Dedicated before the Demons made contact.
Best of luck!
HS!