Fluid mechanics is the study of fluids and the forces on them. When we say fluids it includes both liquids and gases. It Involves various properties of the fluid, such as velocity, pressure, density and temperature, as functions of space and time. This websites incorporates concepts such as Bernoulli's principle, flow rates etc. which you can dig into.
Thermal physics is essentially the study of heat, temperature, and heat transfer. All of these concepts are closely related to thermal energy, which is one of the most important forms of energy. You will learn about solids, liquids, gases, and how heat is involved in the phase changes between the three.You will be also learning thermodynamics which relates temperature, volume and pressure together. And you will also be exploring the dynamics of heat engines, entropy etc.