Since there is no background attribute in a text object in SVG, you'd need to use another method, such as drawing a filled rectangle under the text, however as you say that's inconvenient as you'd have to resize the rectangle every time you type a name that's shorter or longer.
One method is to use an SVG filter applied to some text to create a box around ...
The larger, serifed hand is definitely someone's hand-lettered version of a Copperplate (and very nicely rendered at that) and the sans serif looks like an italic variation of one of the bauhaus style hands - I've two near matches but neither is quite perfect.
You can get something kind of similar, by using a modified Blend filter.
Type some white text, and make sure the text object is selected
Click Filters > Fill and Transparency > Blend
Set the source to Background
Open the Filter Editor
Change the Mode to Exclusion
Note: the contrast is not as strong/vivid as your example because effect is dependent on the ...