Please help me to define which tests to apply

Good morning friends, I'm in need of some tips on what tests to apply in R for my research.
My research has the title of seasonal distribution of a species on the coast.
Collected data.
Number of organisms collected in the month. Over the years
Abiotic variables (climatology) Wind speed, wind direction, atmospheric pressure, precipitation, season, average temperature, relative humidity and size of organisms.
General objective

To characterize the seasonal distribution of organisms on beaches in order to understand the interaction of abiotic factors in their agglomeration.

Specific objectives

To verify the existence of seasonality of the organism;

You will correlate agglomerations with abiotic factors (e.g., temperature, salinity, precipitation, wind).

Thank you all for your help :legal: