A particle goes after a word and says what that word is doing. Japanese does not use word order for that the way English does — 犬が猫を見た and 猫を犬が見た both mean the dog saw the cat, because が and を said so. Swap the particles and the cat is doing the looking.
Almost nobody gets a particle wrong because they have not met it. They get it wrong because two of them fit and only one is right.
は says what the sentence is about and treats it as known. が points at it as new or as the answer. Ask yourself whether the listener already had this in mind.
で is where something happens; に is where something is, or where it ends up. If there is an action with a setting, で.
After a movement verb they are near enough interchangeable. へ is the heading, に the arrival — and only に does times, recipients and existing somewhere.
と lists all of it. や lists some of it and implies more.
What it marks, when to reach for it, and it doing its job in a whole sentence — which is the only place a particle means anything.
Sets what the sentence is about. Often the subject, but really it is the thing already on the table — old news, or the thing being contrasted with something else.
Written は and said wa. The only particle that lies about itself.
Marks who or what is doing it, when that is the new or the important part. Answers to who-questions take が, and so do most things that simply exist or are wanted.
Marks the thing the verb happens to. Also the road you walk along or the place you leave — the ground the movement covers.
Written を, said o. Used for nothing else, so seeing it is a relief.
A point. The place you arrive at, the time on the clock, the person who receives. Where something simply is, with いる and ある.
The setting an action takes place in, or the tool it is done with. If something is happening there, で; if something is only sitting there, に.
The direction of travel, where に would be the destination reached. Often interchangeable with に after a movement verb; へ leans on the heading, に on the arriving.
Written へ and said e. The second particle that lies.
Joins two nouns, the owner first: わたしの本 is my book. Does the work of English's apostrophe-s and of 'of', in the opposite order.
Joins nouns into a complete list, and marks the person you did it with. For an incomplete list — some of the things — use や.
Lists examples rather than everything — bread and eggs and whatever else.
Replaces は, が or を rather than joining them. わたしも means me too — you cannot say わたしはも.
Where something starts, in place or in time. After a clause, because.
Where something stops. Pairs with から more often than not.
Comparison. The thing that loses takes より.
Turns a statement into a question. Between nouns, it means or.
At the end, inviting the listener to agree. Softens everything.
At the end, when you are giving information they do not have.