"Je fais" means "I do" and "de la" means "of the". How can this sentence mean "I play pétanque"? I am having trouble with article contractions.
You have to understand a basic principle before going too far in the study of a language. Just as in your mother tongue the forms used have been handed down to the users of the language from a long tradition, although as time went by some changes were made. The forms we use today correspond to fixed meanings and that is all there is to it : you are dealing with established correspondences for whih logic is no absolute help. There is a certain logic in them, but they are not wholly founded on logic. In particular the logic that is valid in your mother tongue will often be of no help in the studied language.
For instance, taking the verb "to make" (faire), in English you say "I made (some) bread", "I made (some) tea.", "I made (some) jam.", perhaps using the partitive article "some". This is an idiomatic choice, proper to English only: you have two options. In French the idiomatic choice is of one sort only: you must use the partitive article ("du", "de la", "des") and so you say "J'ai fait du pain.", "J'ai fait du thé.", "J'ai fait de la confiture.", etc. This is the idiomatic way to use "faire" when "faire" means "to prepare (sth)". When "faire" means "to construct, " the English "logic" corresponds often to the French "logic": in both cases you use no preposition or word: (I made a round on my notebook./J'ai fait un rond sur mon cahier.), (He made a bow./Il a fait un arc.), etc. There are more often than not reasons for that, they are to be sought in the history of the language but you do not have to worry about these explanations of the coincidences (studying those explanations is specialist's work and you don't need it to progress in the study of your foreign language). Moreover, there is no rule telling you when there is a coincidence.
In the case of "faire" meaning "to play a sport or an instrument" or "to study a subject", in French usage has it that a preposition must be used (that is "de"); "usage" is a term like "idiomatism" connoting the idea of something that can't be explained too well or not at all and that we have to accept as it is.
Thus, you say
"faire de la pétanque/natation/gymnastique/marche à pied/voile/bicyclette/culture physique/etc." (feminine words beginning with a consonant),
"faire du sport/kayak/tir à l'arc/vol à voile/tennis/rugby/etc." (masculine words beginning with a consonant),
"faire "de l'athlétisme/alpinisme/escrime/etc." (masculine words beginning with a vowel),
"faire de l'équitation/etc" (feminine words beginning with a vowel).
The same principles are applied for instruments and subjects: "faire de la clarinette", faire du piano", etc.
faire de la chimie/de l'histoire/du calcul mental/du droit/etc.
Despite a certain regularity, as you might be beginning to notice by now, the system is not too nice, there are exceptions and you have to be careful. For instance, you do not say "faire du tambour"; instead you say "jouer du tambour".