@Vickienonprofit Depends on what you mean by "to combine". If Both sheets have the same lay-out (i.e. columns with similar information in the same place) you could just copy one set of data and paste it below the other. Excel can handle up to just over a million rows of data.
If the other data set contains different information but shares unique identifiers with the first data set, you perhaps want to merge the data. Then, Power query is probably the best option.