I have used each one of these programs so I can vouch for each one. They will make a world of difference for you as they did for me.
This is my holy grail out of all of these. I have the monthly subscription so I can get all the answers to homework that I need whenever I want. You can use it without the subscription ($14.95/month), but are limited. This site is also great for ordering textbooks.
2. Course Hero
I do not have this subscription so I can only use it in a limited way, but you get three sneak peeks per month so take advantage of that!
I personally use this website because I work from a Google Chromebook. The Google Doc app does not have a word count feature, so I had to look elsewhere. This site also shows you things such as the reading level, how long it would take to read and how long it would take to speak aloud in case you needed to know for a speech.
4. Wolfram Alpha
This program specializes in math. It gives you step by step instructions towards the answer.
Quizlet is an online flashcard simulation. It is made by other users who have taken the same classes as you. It's great for studying!
This site is the same concept as Quizlet. Sometimes one will have the answers you need that the other may not.
YouTube can be thought of as just watching funny videos. makeup tutorials or vlogs, however, it also is a great resource for studying. There are real-life teachers that make channels to talk you through concepts.
Don't let the stress of school overwhelm you! Use the great technology we have been gifted with to help you succeed.