The first thing I recommend is that you check with your county's extension office. They can provide you with something like this. This is where you'll put your soil sample so you can send it to them for analysis.Then, identify the area you want to test. In the grassy area, select sections of the yard at random, making sure the entire area is covered. All of the dirt from all of those sites equals one sample. Put it in a bucket and let it dry out. Then, mix it up thoroughly. Select one scoop for your sample. Put it in the bag and send it to your extension office.
To test the soil in your flowerbeds, follow the same process but do not mix your sample with that from the yard.
When you get the results, you'll get a sheet something like this that tells you what the pH level in your soil is. You'll also be able to tell what nutrients (such as hydrogen, potassium and phosphorus) your soil can provide plants.
If the pH level in your soil is too acidic, you will need to add lime to balance it out. If there is too much alkaline in your soil, add aluminum sulfate.
You might be tempted to check your soil using one of the test kits sold at local stores. But those results just aren't as reliable as those you get from your county extension office.
So remember, before you plant anything, dig up a little dirt to see what kind of soil you have. Send your sample to your extension office. Then make adjustments to your soil based on that recommendation.