What knowledge? Please give more details and show whatever you've tried. For example, are you looking for the pdf, cdf, or mean of the sum of two independent random variables with one having a Nakagami distribution and the other having a Gaussian distribution? And...is this a statistics question or a question as to how to implement this in Mathematica?

It would be nice if the following worked:

dist = TransformedDistribution[x1 + x2, {x1 \[Distributed] NormalDistribution[\[Mu], \[Sigma]], 
   x2 \[Distributed] NakagamiDistribution[m, \[CapitalOmega]]}, 
  Assumptions -> {m >= 1/2, \[CapitalOmega] > 0, \[Sigma] > 0}]
PDF[dist, z]

But at least for Mathematica 12.0, it doesn't. That means doing this the old-fashioned way by integrating over the joint distribution of the two random variables:

Integrate[(2 E^(-((m x1^2)/\[CapitalOmega])) x1^(-1 + 2 m) (m/\[CapitalOmega])^m)/Gamma[m]
  E^(-((z - x1 - \[Mu])^2/(2 \[Sigma]^2)))/(Sqrt[2 \[Pi]] \[Sigma]), {x1, 0, \[Infinity]}, 
  Assumptions -> {m >= 1/2, \[CapitalOmega] > 0, \[Sigma] > 0}]

The result for the pdf is