By if condition i mean something like programming but in blueprints
Use the Branch node 
If you right clic to open the menu in a BP and just type “if”, the Branch node will pop.
Making if-conditions is a problem whose solution is easily googled…
Thanks , is there any guide on how to use it
Ok so in sort you use a Branch node that when if reads a bool it has either a true or false path that flows from this node to do what ever next section of Blueprint scrips are.
You can also create bools based on your basic less then(or less then or equal), equal or greater then(as well as greater then or equal). Basically just use a value (for example a float) and drag a pin from it and type in less then and you’ll see that less then or equal node. Again this will just create a bool value that you can feed into a branch that you use to control the flow of your Blueprint graph.
If you google “Deventico”, I believe it comes up with a Wikipedia article relating to the most helpful UE4 forum user of 2015.