How i connect my home ubuntu server with any domain and access outside network

I have an old computer and i have converted into ubuntu server i have installed openssh apache2 and php .I can access it on the network but now i am find a way to connect my server with my domain and access the server like we access aws servers.Actually i want to use my home server other then aws servers.But i can’t find any tutorial related to this.Every one just connecting it on network but i want to connect it outside my office like i access amazon servers

Can any one explain it setup by setup or any video tutorial .

Thanks in advance.