Can you play in Minecraft in single player online without having the same internet connection?

I want to play with friend

I don't know if that answers your question, but at Aternos you can set up a server for free.

You can also upload your single player world there. (Can help you there if you want)

Host the server yourself

I'll try if I'm not sheep then I'll ask you

Ok i need help on how to add mods

I haven't dealt with that myself either. But you have to install other software (e.g. Forge) and then you can add mods. To get on the server you need the same mods.

OK thanks