are there any trains in walking distant or anywhere at all to my family is coming from Brooklyn and Manhattan to attend a gathering in the park.

yes. take the 1 Train to 145th St. The park is two blocks over. transfer from the 2 to 1 at 96th st. Or take the 4 train to 149th in the Bronx and transfer to 19 bus towards Manhattan. The bus last stop is in the park. The one train will leave you two blocks from the park.

#1 train to 145st station,the entrance to to park is down the hill on the McDonald's side of the street

Yes, There's every subways!