efamily71,
Remove and clean the filters. Unplug the spa or turn breaker off. Fill the spa and check the connections in the equipment compartment. Check for leaks. Make sure all the unions are tight and not leaking. After the spa is full turn the breaker on or plug it in. If there is an electronic control pad you should have some lights on. Press the filter mode. The circulation pump should start. You may not hear this pump because it is a very small pump designed to run 24/7. You should see a slight movement of water. Then try the jet pump(s). There are a couple reset buttons on most models. One for the heater and one for the spa. You should also have a door switch shut off on the equipment compartment door. Everything shuts down when the door is slightly open. This is a safety feature. Once you get the equipment running, reinstall the filters. All of the pumps run thru the filters. One filter will normally be dirtier than the rest. This is the one that the 24/7 pump runs thru. Once the heater is on it will take about 6 hours to heat the spa. Use the cover for efficiency.
You should be able to find a model number as well as the serial number. The model number can be located under the skimmer lid on older models or inside the equipment door. The model designations are general letters GR for grandee, SN for soverign. So look for a letter designation in front of the serial #.
Water chemistry is important. Check and see if you have an ozonator installed at the equipment. This has been pretty standard on the newer models. Buy a test kit, bromine and dry acid to start. You should be able to get a little advice from the local pool supply store.
It may be necessary to drain the spa after you have filled it the first time. There could be a lot of bad water sitting in the plumbing after the first go round. good luck.

Hopefully, you've made progress on using your hot tub. We've had 2 different ones over the years & it's been a wonderful family activity as well as for company.

Make sure you super shock because there can be bacteria in the "old water" in the pipes and this same bacteria can grow anytime your chlorine/bromine level drops below 3.

A pool supply store can help teach you the routine maintenance necessary to keep your family safe from the bacteria that can grow in a hot tub.

Then teach everyone in the family who would use it to always put the amount of chemical as suggested from the store in after each use even a quick dip. If you do that it will be hassle free.

In recent years we added a cover lifter. It's worth the money because as the cover ages it gets heavier & harder to lift. When it's cold outside you want to get in quickly not stand there trying to lift the cover off.

Hope that helps!