Advice Wanted: 100 Unit Property for 1st Deal??

My husband and I are new to investing.

I have been interested in real estate investing for many years, but by husband just got on board when he became good friends with a local investor who owns multiple large apartment complexes in our area. This friend has happily taken on the role as a mentor to my husband.  The friend / mentor found a 100 unit property that he thinks could be a good deal for us. My husband and I can only afford a 2-4 unit property on our own, so the mentor has offered to either partner on the deal or be our private money lender.  My husband trusts his mentor completely and is entertaining the idea. I, on the other hand,  am terrified of taking on that many doors with ZERO landlord experience. Also, having a mentor is great, but don't want our friendship to be tainted by business dealings.

I would really appreciate any advice. Should I trust the experienced mentor, or is this many doors ridiculous for a 1st deal?  What are your thoughts?