Syndications can be helpful to help gain insight and experience into the multifamily space.

Learn the ropes and gain experience through others.

@Aqil Dharamsey,A good handyman is worth their weight in gold, and as others have stated-- are part of your competitive advantage.   

My other thought is that I just continue to live in the property that I am now to reap the tax benefits from living in the property for two of the first 5 years to avoid paying capital gains tax.

He’s now looking at selling the property with significant gains.

This seems clear.Sell and not pay capital gains because you've lived in it?

Still renting out, house has gained over $50k in equity and will only go up!

When the taxpayers demolished their existing principal residence, built a new home on the land, and sold it before ever occupying it, the Tax Court ruled the gain resulting from the sale of the never-occupied home did not qualify for exclusion under IRC Sec. 121 (Court case: Gates).Not sure if Gates applies here, because nothing would be added to the formerly residential land, only removed from it.

My duplex has gained about $50K in equity and I'm wondering if I should use that equity towards purchasing another property?

Hopefully you can gain access and get the property cleaned up.