I'm a second year at Lancaster University studying in the Lancaster Environment Centre (LEC) so I can't speak for postgrad MSc modules, but so far I've really enjoyed studying here at Lancaster. The LEC department is the biggest in the university, which means there are a lot of exciting modules to choose from and specialise in, especially at postgraduate level. For example, there are research groups in political ecology, critical geographies, volcanology, crop science, climatology and water science among others, and this really feeds through into taught modules.
One thing I've really enjoyed about studying so far is the field trips I've had for modules such as atmospheric science and catchment hydrology. Being so close to the Lake District, the Forest of Bowland AONB, Silverdale AONB and the Yorkshire Dales means that there are plenty of accessible sites for fieldwork nearby. Additionally, there is the opportunity to go on longer fieldtrips to locations such as Croatia and Switzerland, where water science and management of alpine environments are studied respectively.
In terms of understanding modules, there are plenty of workshops and opportunities during lectures to ask questions. Additionally, you are free to contact lectures via email or Teams, or many lecturers are happy to talk if you go to their office. I've always found the lecturers in Lancaster Environment Centre to be really friendly and open to discussions, whether they're about a difficulty you have in understanding a topic or an area of their research that you're interested in.
One module I found quite difficult was a GIS module, however the lecturers were really helpful and there are specialised GIS technicians in the department who you can go to for help as well.
Hope this helps,