Welcome to the forum.
1. If what you are calling mesh line you mean grid lines go to Tools>Options>Document properties>grid
In there you will find a check box that toggles the grid on/off.
2. Not sure what you are talking about when you say the symbols boundary settings.
Can you be more descriptive or post an image of what you are talking about?
To see the mesh, right mouse on the plot in the tree and go to "Settings" and change the boundary option to Mesh.
To not show symbols, right mouse on "fixtures" and "external loads" folders in your tree and "Hide All"
Thanks Scott and Wayne. In fact, Wayne got cross my question and answered it right. Good start with me in learing SW simulation.