Assuming that the numbers are typed text and not automatic numbers then you need a macro. It is not clear whether you want the paragraph or just the number bold, but I have included optional code for either
Installing Macros :
Code:
Sub Macro1()
'Graham Mayor - https://www.gmayor.com - Last updated - 20 Aug 2019
Dim oRng As Range
Set oRng = ActiveDocument.Range
With oRng.Find
Do While .Execute(FindText:="[0-9]{1,} [A-Z]", MatchWildcards:=True)
If oRng.Start = oRng.Paragraphs(1).Range.Start Then
'bold just the number
'oRng.End = oRng.End - 2
'oRng.Font.Bold = True
'bold the whole paragraph
oRng.Paragraphs(1).Range.Font.Bold = True
End If
oRng.Collapse 0
Loop
End With
Set oRng = Nothing
End Sub