I don't go to dog parks because the three closest to me are tiny, 2, 7 and 20 acres. You might not think the latter two are that small but the 7 acre one has a hill, people can't, or won't, climb the hill so everyone congregates at the gate - bingo - problems. The 20 acre one is long and narrow, has some nice bush, but again, people don't walk to the end and even if they did, it's crowded at the entry/exit. So, can you use the whole 88 acres?
Fence, it must be fenced. I tried the 7 acre one once. It bordered a busy, high speed highway and the fence was not secure, broken right down in some places. Very dangerous.
Have you looked into what insurance you'd have to carry?