Use & to separate query string options
Use $filter to filter the data (see here):
community.innovacall.local/odata/contactcompetencies?$filter=id eq 1
Use guid'<value>' for guids (see here)
community.innovacall.local/odata/contactcompetencies?$filter=id eq guid'4a50412c-4e36-468a-b7d1-a36a78f02b02'
Use $inlinecount=allpages to get a count of records (see here)
community.innovacall.local/odata/contactcompetencies?$filter=id eq guid'4a50412c-4e36-468a-b7d1-a36a78f02b02'&$inlinecount=allpages
Use $top and $skip to page through the results (see here and here)
community.innovacall.local/odata/contactcompetencies?$filter=id eq guid'4a50412c-4e36-468a-b7d1-a36a78f02b02'&$inlinecount=allpages&$top=10&$skip=10