On Chol Moed one is allowed to do melachos that are for the needs of the festival. What exactly does that mean? Can I just get into my car and drive to the store even if I can walk to the store as well? Driving in the car is helping me during the festival but I don’t always “need” to drive everywhere. Also, people go apple picking and fishing which are melachos on shabbos. Are they considered a need for the festival if the purpose is for pleasure or entertainment. I don’t really need the apples or the fish. Are pleasure melachos considered a need?
It is permitted on chol hamoed to perform melachos that are considered a maaseh hedyot, meaning melachos that do not require an expert craftsman, provided they are done for a need of Yom Tov (Shulchan Aruch 541:1).
The cases mentioned in the question are all considered “needs,” for the definition of a need (in this context) is not something you can’t do without, but rather something purposeful that you wish to utilize now. This includes saving the trouble of walking down the road, or the pleasure of fishing.
Note also that are some melachos, such as carrying into the public domain, cooking, or lighting a fire (switching on a light), which are generally performed without considering the need for them (see Amudei Ohr (35), who finds this difficult; see Moadim U-zemanim, 298). To explain this, some have written that those melachos that are permitted to perform on Yom Tov for the purpose of ochel nefesh, are entirely permitted on chol hamo’ed (see Minchas Moshe, Orach Chaim 56).