If you do not have much experience in SharePoint, i can recommend SPDocKit. It makes an inventory of your farm within seconds and without installation.
What you need from there is the "Bestp-Practices Report". Unfortunately it contains a lot of Best Practices which only apply to some customers (e.g. Enabling BLOB-Cache). So you need some experience to interpret the results. Not every red cross means you have to fix that.
Some tips:
- Do not expect a "Full Installation". There are components which do not make sense to configure for a majority of customers but cost time to get them running properly (e.g. AccessServices) or cost extra money (e.g. Reporting-Services for SharePoint).
- Installation should be performed with PowerShell-Scripts. Either own-written scripts or AutoSPInstaller. If installation and Service-Application creation is performed via GUI, you should not accept the farm.
- CentralAdmin has a ton of links. Finding what you need there is hard for beginners. SharePoint guys with an experience greater one year should find entries in CentralAdmin very fast. If he seeks around you might have a junior.
- SQL-Server gets installed by most SharePoint Consultants in a "Next next finish" way. But there is lots of possible optimization for stability and performance. Look what he does there.
- Even if it costs money: Claim a documentation of what was installed and what was configured after installation.