And all applications should go on my sd card instead of ram, right?
Yes, select SD for the destination when you use ipkg.
And for installing ipkg, do I need internet or not?
ipkg is installed already, it's what the GUI package-manger uses, however it appears that there are some minor issues with the GUI package-manager.
I always use ipkg from the command line.
It seems it downloads off of the internet when using the package manager.
ipkg does this, yes, if you have internet access, it means you don't need to carry the entire feed around with you, you can just access it at will.
You were trying to install wellenreiter - try running: 'ipkg update && ipkg install -d sd wellenreiter' (that said I don't know whether it's in the feed, but you'll find soon out).
Si