By default, \&
is just &
from the current font tex has no control over it. So choosing the shape of &
is like choosing the shape of g
: you just need to pick a font that you like.
However if you really want to change \&
while keeping the same font then...

\documentclass{article}
\begin{document}
\catcode`\&=12 % make & a normal punctuation character not a table cell separator
abc \& xyz is the same as abc & xyz.
Like g it shows a lot of variation
g & \textit{g &} \textsf{g &} {\fontfamily{ptm}\selectfont g &}
But being a command you can redefin it to be anything
0 abc \& xyz
1\renewcommand\&{{\tiny&}} abc \& xyz
2\renewcommand\&{\raisebox{-.3ex}{&}} abc \& xyz
3\renewcommand\&{{\large\bfseries AND}} abc \& xyz
\end{document}
\&
is just&
from the current font tex has no control over it. So choosing the shape of & is like choosing the shape of g you just need to pick a font that you like. – David Carlisle Jan 4 '18 at 20:59