Blade type & size (number) USUALLY depends on your personal preferences. Of course as a real beginner, you won't have developed any yet!
So we make it "easy peasy" here! Go to the sticky thread at the top of this Scrolling & Scroll Saws section. You'll find a downloadable "No Fail Blade Chart" which is always a good place for a beginner to start. There are also downloadable charts from one of the well-known manufacturers (Pegas) showing ALL the blades they make (wood AND metal, plus coping saw and junior hacksaw blades); and details of other popular/well-known blades. PLUS details of where to buy.
ALSO, I don't know much about Hegner machines myself, but there are two very Hegner-knowledgeable members here - "scrimper" and "loose nuts". If one of those two gents doesn't appear here soon, then send either/both of them a PM.
HTH
Edit for P.S. As a beginner I'd also strongly recommend an online visit to one or two US specialist scrolling websites. For e.g. search for Steve Good.
And another P.S. NOT taking the mickey ('onest) but getting the spelling right will help your searching tremendously - it's HEGNER
Mod edit: fixed.