Teach me, Senpai. How do I do this hosting?

[VanillaDucky]

Hello. I used to host my own Unturned server through a server hosting website. I decided to host a modpack, but I have no knowledge with it. So I asking this community to give me a hand for me to hold on and walk. I don't know which website are best and cheap to host a server for a modpack. I'm looking to spend about $30 USD maximum. Do I want to use bukkit for this? If so then how bukkit work? How do I add modpack to server files? How do I add plugins to server files? Any hints and tips? Thank you for your time to read and reply. 

[HallowedCommunity]

Modpacks Generally have custom Jar files, Any Public host should provide this.
Considering your budget is only $30, I Recommend bisectHosting due to working with them for a variety of years, They seem reliable.

[TheLastSpectre]

You can technically host it yourself for free, as long as you don't intend for too many people to be playing on it as it will eat up alot of Internet. To add more mods, simply download the mod off the internet (Curse Forge is reliable) for the appropriate version of Minecraft, navigate to the .Technic folder (Users/Your user/AppData/Roaming/.technic/modpacks/whatever modpacks you are using/mods. Then place the file into the mods folder and restart the server.