Yes. That should be fine. The only thing i would say is that it is quite common for plants from the LFS to have snails or snail eggs on them which once in your tank can get quickly out of control, so its always worth giving the plants a wash under the tap before putting them in the tank.
Hi, You will probably get a better responce if you post your question in the plants and planted tanks section on this forum. I planted my tank up initaially after i put fish in. The only thing was the lighting was poor so i had to upgrade to 4 strip lights. T5 lights are better than T8's. Lighting is really important for plant growth. My plants kept on dying even after upgrade so i installed CO2 and a good fertilizer.
Generally it is fine. If the plants are kept with fish at the store, there is a possibility of them bringing diseases with them.
Otherwise, give them a good wash under the tap or a minute in a mild bleach solution (depends on the plant type how much they can take) to remove snails/snail eggs.