Decimal degrees will still use geographic degrees as the distance unit in the Buffer processing algorithm.
You can either reproject your layer to a projected coordinate system by right clicking the layer and selecting export --> save features as --> and save it to a vector format such as
geopackage or shapefile and select a projected CRS appropriate for your zone (e.g. EPSG: 32651). The buffer tool will then use meters as distance unit.
Or, a much quicker and in my opinion, better way would be to create a buffer using a virtual layer.
Go to Layer --> Add layer --> Add/edit virtual layer and use something like this as your query.
select st_buffer(st_transform(geometry, 32651), 100) from Calapan_XYpoints
Just change the
100 argument to your required buffer distance in meters