Sql Server 2014 update path advice

I recently inherited a SQL Server 2014 installation and I'd like to install updates. The virtual machine runs Windows Server 2016 standard. The server has about 50+ databases with 400Gb of data. I'm a developer and don't have much DBA knowledge. Current plan is to update SQL Server to 2014 SP3 (right now it's RTM). Are there any problems I should be aware of? I do plan on trying it out on a non-production server first - but unfortunately can't get the same exact Windows version. Is there some script or utility to healthcheck SQL Server installation? I doubt that manually running sql statements will be very thorough. I only found Brent Ozar's blitz so far.