There are many self paced online courses that can help you in learning how to use Simulink for your simulations. The courses 'Simulink Onramp' and 'Circuit Simulation Onramp' would be best suited for your requirements. Here's some links to these courses.
'Simulink Onramp': https://matlabacademy.mathworks.com/details/simulink-onramp/simulink
'Circuit Simulation Onramp': https://matlabacademy.mathworks.com/details/circuit-simulation-onramp/circuits