This paper presents an optimal energy management and sizing of a smart community microgrid (MG) with the uncertainty in load demand. An isolated small scale microgrid is considered with no access to the main supply grid. For simplicity, a small community of 15 houses located in a remote area is considered, and the loads are divided into controllable and uncontrollable categories. Demand side management (DSM) is being utilized to produce a feasible alteration to the controllable part of the load. The Overall problem is formulated to fix the optimal size of distributed generations (DGs) used in the MG by using a heuristic approach to minimize the net cost-based optimization problem. This cost includes initial capital costs, operation, and maintenance costs, and other running costs associated with MG. The optimization is completed in two parts. The first part of optimization is done without DSM implementation, and second part optimization is done on the modified system peak load after DSM implementation. Quantitative results on a numerical case study give an optimal number of distributed generation (DGs), their corresponding optimal ratings, optimal cost value, reduction in carbon footprint, and annual cost savings in the form of CO2 emission tax.