Thanks for the link. I’ve made a copy of your project and set up an example of how I would analyse this structure.
Here is a link to my example project. https://www.simscale.com/projects/BenLewis/solar_panel_frame/
There are lots of ways to check wind loading. Most countries have standards you can use for this purpose. They are usually quite complex and include such things as regional wind speed, orientation, terrain, shielding, topography, shape factor etc. You can use CDF to calculate the loads from a given wind speed. You can also use simple hand calculations for an approximate value. I have used the hand calculations below.
Fixed supports should be added to the base of your legs. To incorporate the structural members they need to be connected to each other. You can do this with contact definitions, or, as I have done, combine them in your CAD tool.
Usually it is not necessary to include fasteners. Just make sure your bolted connections are adequately sized to carry the expected loads.
Note, my example project is just something I’ve thrown together quickly to demonstrate the concepts. It is not intended to be a fully worked solution.
I hope this helps.