Amortization is basically an accounting technique for periodically lowering the book value of the loan. To make it clear we need to understand that our monthly payments have 2 parts: interest part cost of the loan, principle the main part. These are calculated monthly with the same interest rate we use, but keep that in mind every month we have less debt as we paid some already. So when you do these calculations monthly and write them down a table of payments, we call it amortization schedule.
Here is the simplest and most detailed video I could find.
You can imagine increasing the loan amount is just adding more risk in the long term. But if you don't have any savings and just applying for a loan increasing it as 1-2 months of payment might be a good idea. You can keep them in a saving account as insurance. Again need to mention these are totally depending on your conditions, earnings, savings, credits score etc. so any advice given here are totally personal and need to think twice before apply them.
Another thing is be careful with your due dates and make sure you are at least paying the minimum. If you struggling with it or interest rates are too high, you can consider negotiating this with your bank or even some banks offers loans with lower rates and transfers your debt to theirs if you can convince them that you are on good track.