That is correct. The rule is quite simple for the past tense -- in the past tense, when you use an auxiliary verb (like 'had', 'was', 'could have' etc) always use the past participle form, and always use the simple past form when not using auxiliary verbs.
Yep, yep. Another easy way to think of it is simply to remember verbs as threesomes:
ride, rode, ridden
hide, hid, hidden
eat, ate, eaten
swim, swam, swum
sing, sang, sung
drink, drank, drunk
speak, spoke, spoken
etc.
Then just note this fact: #1 of the threesome is the present tense; #2 is the simple past; #3 goes with auxiliaries.
The only reason people get confused about which one to use with auxiliaries is that for many English verbs (generally the ones with a past tense in -ed), #2 and #3 are the same:
lead, led, led
love, loved, loved
talk, talked, talked
etc.
So the only trick is remembering which verbs do NOT have the same form in both #2 and #3. That's where dictionaries can come in handy (who knew the #3 for "strive" was "striven"?!? Although actually that verb has come to have two forms: strive, strove, striven or strive, strived, strived could probably both be considered correct.) But if you already know they're not the same (e.g. you know the words rode and ridden both exist), then you know you have to use #3 with auxiliaries.