You should take a look at the software portal of your university. If you have to use it for educational purposes, your university propably has the software and licenses available there.

After downloading, which will take a while, you should take a look at some of the theory and basic examples at maplesoft.com

For ODE's use dsolve(), and look at the examples at https://www.maplesoft.com/support/help/Maple/view.aspx?path=dsolve
For PDE's you can take a look at : https://www.maplesoft.com/support/help/Maple/view.aspx?path=pdsolve

you can most certainly find solutions to your questions regarding syntax in your first problems through your favourite search engine, This will save you a lot of time.

Good luck with exploring Maple and solving your assignments