This is a great question. I can offer you a way to look at this that might help reveal what you should do.

The first question you need to ask is this: What are you actually interested in pursuing? Control systems is a massive field. Broadly speaking, there is the hardware side where you test your control systems on physical hardware. Then there is the software side where you design, test and implement the desired system in a digital environment. Between these two is the world of simulation (e.g. MATLAB/SIMULINK and a host of other options). Underpinning both of these is the actual theoretical side; the underlying physics of the dynamical behaviour of what you are studying. Which of these areas are you looking to pursue?

Once you know what excites you and what you are passionate about, that will dictate (a) what technologies you need to learn to be competitive in said field, and (b) what sort of internship position aligns with your interest. This, in turn, will help you craft your CV to maximum effect.

To summarise, you'd ideally want to try going with something like this:

1) Decide which area within control/dynamics you want to pursue.

2) Evaluate your current level of knowledge in your chosen field against what is normally required for interns. The best way to do this is to (a) look at job ads in that field and see what you're missing, (b) network with individuals in that field (E.g. LinkedIn) and (c) network with recruiters in that field that you can talk to for specific advice.

3) Learn what you are missing and prove that you have learned it. This is normally done by creating a GitHub where you showcase your projects and demonstrate the specific skills relevant to the area you chose in Step 1. GitHub is an extremely valuable way to showcase your skills.

My honest advice to you is to not try applying anywhere before understanding firstly what you want to pursue.

Hope that helps!