You are responsible for entering a holding pattern correctly. The standard entry procedure depends on your heading as you approach the fix.
Standard holding patterns assume right turns. The entry is divided into three zones:
Direct entry: If you are on the inbound track or within 110 degrees of it (either side), you fly directly into the holding pattern. You will not need a procedure turn.
Teardrop entry: If your heading is between 110 and 180 degrees off the inbound track, you fly into the holding airspace on a teardrop path, make one left turn, and rejoin the inbound leg.
Parallel entry: If your heading is between 180 and 250 degrees off the inbound track, you fly parallel to the outbound leg, make a left turn to parallel the inbound leg, then make another left turn to rejoin the inbound leg.
For non-standard (left-turn) holding patterns, reverse the entry procedures.