Liam Delap had the hosts ahead before fired back through Adama Traore before halftime.
McKenna said: "It is a step in the right direction, and so was the performance. We are adapting to the level, improving all the time and integrating players all the time, we had six players who have joined us this summer.
"We were competing against a well-established team at this level so to compete how we did is a positive and we feel we have lots to come.
"Some of our pressing in the first half was excellent, and the organisation and discipline against a team that can give you problems was really, really good."
On goalscorer Delap, he added: "We are happy with how he is progressing, he is still getting up to speed after an injury at the back end of last season, and is improving all the time. He is taking lessons, taking in things really well and we feel he has a lot of growth left in him."