Business assets or expenses?

My business does data processing (data transaction validating).  Are the computers that I use to do the validating considered assets or expenses?  The first year (2017) I had a revenue of just over $7k, but had nearly $60k in expenses and/or asset purchases.  The second year (2018) I had a revenue of just over $50k with about $30k in expenses and/or asset purchases.  Last year (2019) I had about $14k revenue and I don't even know what the expenses/assets are yet.  I'm probably getting out of the business this year and just want to know the best way to about all this.  And yes, I'm just now going back and amending my previous couple of returns as there is more guidance now on the tax rules for my business.