what camera are you using?
A cheap macro is the sigma 50mm that is available for most cameras.
A cheap alternative to a macro lens are macro/close up filters.
The hood for your sigma 70-300mm is fine, a tulip hood will not make a massive difference. If your lens does not come with a hood then a specific type should be available for it. Again what lens/camera combo are you using
Teleconverters are overrated
imo, cheap teleconverters are poor quality, plus with slower (higher aperture number) lenses you will lose autofocus. Better off cropping unless you have good quality fast telephotos and a good quality (expensive) teleconverter