LT-spice-Simulation model for PV panel
In your first picture, you have two resistors, Rs and Rp. These are their reference designators. Their values are, by default, an undefined R, which needs to be changed into something that will evaluate to a numeric value. In your case, it looks like you defined some values, named after the reference designators, Rp and Rs, but you have not assigned them. For this, replace both relevant R into {Rp} and {Rs} (curly braces included). They should look something like this:

The second error tells you about F1, which needs to take a current through a voltage source, and have a multiplying value attached to it. In your case, it looks like it needs to take the current through Epv, but I don't know what value you should assign to it. Try modifying Fcell to Epv 1, but you should really check your source for details about this.
However, it looks like you could use an introductory tutorial about how to use LTspice. It would be very recommended to follow one -- there are plenty on the net -- otherwise you'll just stumble after every little step you encounter. In other words, know the tool before using it, though nobody says you have to be a professional about it -- just enough to be able to use it without frustrations.
One of them might be loading the output with a voltage source (Vpv in your 2nd picture). That is meant to be the output of the panel.