Following the documentation of the calligra
package at http://ctan.org/pkg/calligra, try this minimal example:
\documentclass{article}
\usepackage{calligra}
\usepackage[T1]{fontenc}
\begin{document}
Fee, fi, fo, fum.
{\calligra Foo bar bas; quux!}
\end{document}
Note that loading the package enables the \calligra
command to change the font. The package also provides the \textcalligra{}
command to set runs of text in that font. Either option is more convenient than loading the font yourself.
If you want to load the font yourself however, try \fontfamily{calligra}
, with the font name in lowercase. (Take a look at how the package loads the font for an example; or see Herbert’s answer for details.)
If these don't work, then perhaps the font package is not installed. It is available under both MiKTeX and TeX Live; see your distribution’s instructions for installing packages.
This particular font is not available at the size you require (if you read the log LaTeX tells you that it has substituted a font). Scale it manually to suit, using scalebox
.
\documentclass[oneside, 11pt]{memoir}
\usepackage{yfonts, graphicx}
\usepackage{lettrine}
\begin{document}
\lettrine[lines=3]{\gothfamily\fontsize{50}{60}\scalebox{2}{L}}{orem} ipsum dolor sit amet, consectetur adipisici elit, sed eiusmod tempor incidunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquid ex ea commodi consequat. Quis aute iure reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.
\end{document}
You can change the \fontsize{50}{60}
to higher values and you can observe the fact that no larger font size is available. Best of course to change my MWE to a small macro rather than lump the parameters with the text.

Scaling fonts this way is not a very good idea. Artistically when fonts are scaled up or down they use mathematical formulae to compensate for various parameters that affect their aesthetics. Best to find a scalable font.
To change the point size as per egreg's comments try this.
\documentclass[oneside, 11pt]{memoir}
\usepackage{yfonts, graphicx}
\DeclareFontShape{LYG}{ygoth}{m}{n}{<-> ygoth}{}
\usepackage{lettrine}
\begin{document}
\lettrine[lines=3]{\gothfamily\fontsize{48pt}{50pt}\selectfont L}{orem} ipsum dolor sit amet, consectetur adipisici elit, sed eiusmod tempor incidunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquid ex ea commodi consequat. Quis aute iure reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.
\end{document}
Best Answer
Using special font packages this can be done with special commands such as
\gothfamily
oregothfamily
etc. The precise command depends on the font and the package and ifXeLaTeX/LuaTeX
orPDFLaTeX
is used.See bookhand fonts for more examples on those kind of fonts.