Good advice! But be careful where you pour fluids until you know for sure what you are doing. Also, make sure you use the correct kind of transmission fluid. It is possible to acquire auto transmission fluid which will damage your transmission. Just ask at the auto store.
On the 90 Loyale, the engine oil check stick is in the front of the engine. Check that often. More often if your Loyale leaks engine oil as most 90 Loyale engines leak unless the front engine main and cam bearing seals have been repaired recently.
On the passenger side (USA) of your 90 Loyale, there are two more oil level sticks to check on an automatic. The stick farthest rearward, which can be found with the spare tire still in place under the hood, although still sometimes a little hard to see, is the auto transmission check stick. Follow the advice given above to check this. This stick, when pulled out, is usually a flat piece of metal.
Under the spare tire, there is another oil level check stick for the transaxle. Do not ignore this level check as oil leaks out of worn axle seals where the axle shafts exit for the front drive axles. You must (?) remove the spare tire to get at this dip stick. Check this fluid level with the engine turned off on level ground. This stick, when pulled out, is usually a round rod which flattens at the fill level indicator area of the rod.
Be aware that the transaxle uses a totally different type of oil than the auto transmission and never the two oils shall mix! The engine oil is also different than either of the other two, just to leave no uncertainties. So there are 3 different oils to check via dipsticks (plus power steering, if equiped).
For any dip stick, be sure to push the stick all the way in when checking the level. Most dip sticks tend to catch at the last half inch or quarter inch where the "cap" or "seal" at the top end of the stick attempts to seal the dip stick tube when fully pushed in.
Hope that helps,
RedCrow