Managing SQL Server MDF and LDF file size
If you just acquired an instance of SQL Server from someone, I would first ask have you gone over the instance configuration and all to understand how the previous person had it configured?

I would suggest taking a look at Brent Ozar's sp_BLITZ script. It is a stored procedure that will collect some good information for you on your instance configuration and give you a good overview of what it sees. I would read over Brent's blog on this script in detail before ever running this on your server, FULLY understand what it is doing.

Regarding your database, are you running out of disk storage or database storage? How much free space does the database contain? I would first understand the architecture of the files before I start making changes. A good article to read on file management is from SQLSkills.com here.

Just my $0.02...