After you underwrite 50 deals in the market, you'll see what the prevailing cap rates are for your chosen property class/size. Just exposure therapy :)
But when you're newer to underwriting deals in that market, then I recommend your best bet is to call 3-4 of the main brokerages (JLL, M&M, CBRE, Berkadia, KW Commercial, Kidder Matthews, NorthMarq, Cushman/Wakefield, Avison Young, Re/Max Commercial, Capstone, etc) ask for a referral to one of their brokers that deals in the size you're looking at, and then simply ask that broker ''hey, I'm new to this market but keep hearing its a great place to invest, can I get 10 minutes of your time to tell me about the market?''
then when you ask your questions, make one of your questions a simple 'what cap rates are A, B, and C deals trading at these days?'
you'll get a variety of answers, but certainly will give you a good idea if 3-4 brokers tell you the same numbers.
Best of luck!