I'm just starting out my journey developing my own board and need some advice how to get started and understand a few things in better context.

I will ask my first question first and provide the preconditions- I need to create a board that supports: bluetooth, audio out, LCD screen, camera, various LEDs. Those are the preconditions; from what I understand ARM Cortex M7 would work quite well for this but do not want to over-do it and need some professional opinions on what you recommend? etc. I would like to stick to ARM here as I have invested some time into understanding it etc. and all the boards I currently have are utilising ARM so it's nice to stick to this.

For my second question here; As a newbie to Electrical Engineering the part that really stalls me is the pins and their functions- I am aware of the different communication protocols and what they do, but there are many other pins on perhaps the ARM board that are not immediately intuitive and connecting the components I mentioned seems like a real challenge and i'm sure it is, so really my question is- are there any great resources to learn these pin functions or does someone have a pin cheat sheet they can point me to so I can advance my understanding on how these components connect with one another and work in an expected fashion. I do understand with every chip there comes a datasheet which one needs to look at but my misunderstanding seems to be coming before this step - probably because I do not have formal education in this domain. Thanks in advance.

I'm just starting out my journey developing my own board and need some advice how to get started and understand a few things in better context.

I will ask my first question first and provide the preconditions- I need to create a board that supports: bluetooth, audio out, LCD screen, camera, various LEDs. Those are the preconditions; from what I understand ARM Cortex M7 would work quite well for this but do not want to over-do it and need some professional opinions on what you recommend? etc. I would like to stick to ARM here as I have invested some time into understanding it etc. and all the boards I currently have are utilising ARM so it's nice to stick to this.

For my second question here; As a newbie to Electrical Engineering the part that really stalls me is the pins and their functions- I am aware of the different communication protocols and what they do, but there are many other pins on perhaps the ARM board that are not immediately intuitive and connecting the components I mentioned seems like a real challenge and i'm sure it is, so really my question is- are there any great resources to learn these pin functions or does someone have a pin cheat sheet they can point me to so I can advance my understanding on how these components connect with one another and work in an expected fashion. I do understand with every chip there comes a datasheet which one needs to look at but my misunderstanding seems to be coming before this step - probably because I do not have formal education in this domain. Thanks in advance.

ADDED INFO- Operation or expected scenario of the board goes like this. User takes photo of them self using their phone as a controller connected via. bluetooth. Photo is taken and sent to the phone where X handles the rest of the process. So really this board has a job of (1) being connected via. bluetooth in bidirectional communication (2) displaying various lights such as red light on green light on etc. (3) playing a voice file that was sent from the users phone which will be played through an audio out speaker.