What is the best way to build/secure an e-learning platform?

I'm about to start my new e-learning business and there's many things i'm concerned about and i hope you can help me. first of all, I've decided to go with wordpress because it's easy and reliable (maybe in the future I will hire a web-developer to build the platform from the scratch but due to budget limitation we can't do this now).

So, my question is :

1- what is the best web host to start with ? (est. bandwith 1000-3000/month)

2- what is the best LMS to go with ? (I want the structure of the site to look like udemy)

3- what is the best best video host to secure my videos from downloading ?

Note: My overall budget is around $600/yr