Tell me what I need in this Fish bowl?

[Virtualworldgirl]

http://www.google.co.nz/imgres?q=plastic+fish+bowl&um=1&hl=en&safe=active& biw=1024&bih=475&tbm=isch&tbnid=EIzox4TGA01-wM:&im

After the eq. People have been leaving free stuff outside their houses due to them leaving and not wanting it, today we drove past a ''FREE'' sign so we stopped and there was a blue fish bowl like in that photo^^^^ and mum said get it and you can get one or two fish.

I really dont want to have to buy a filtre for a small fish tank and i do not think its nessaccerry. So is it safe just to give them oxy shells ( oxygen shells ) or oxygen plants?

Also what else is Nessaccesry or just good to have in a little fish bowl

and do fish get lonely should i get 2 ?

[daniel]

Just get gravel, a plant a rock and 2 fish