Since we have time constraint and are still beginners, how much time it takes to make one custom simulation as a beginner with the initial help from you.

A week or two.

Can you share any resources you have about building these?

I do not really understand this question. If you look at the code comments you will find links to descriptions of the geodesy ( lat and lon, great circles, etc ) calculations

can we have a any other place to have a conversation as this thread is inconvenient and inefficient.

Yes.

The best place is to discuss the code in the code repository ( https://codeberg.org/JamesBremner/MRSnavTestSim ) You will need to create a free account on codeberg, let me know your account name, and I can add you as a collaborator. Then you can open issues, comment on the code and so forth.

..., but if you can mentor me or help me in any means by the term i can say as "collaborating" that would be grateful for me as rookie.

That is the plan.

The boat log is from an ongoing simulation of the boat or something else

The log is from the simulator i have been developing. You can see the code at https://codeberg.org/JamesBremner/MRSnavTestSim/src/branch/main/src

i can send you a progress report in a few days

Is the report written in English?