Where do you intend getting plants from? There are sellers on Ebay, and sites like proshrimp which only sell shrimp safe plants. If the seller does not say shrimp safe, they could be imports from outside the UK and treated with a snail killer.
If they are said to be shrimp safe, the worst you'll get are 'pest' snails which are actually a useful addition to a tank as long as you don't over feed the fish.
If they are in vitro plants, they can be put straight into the tank as there will be no bugs or snails or anything on them. The seller will have a photo of plants in a little tub.
For plants which are shrimp safe but not in vitro - the photo will be of a whole plant with roots, or shown with the roots in a little basket - leave them in a container of water for a week and change the water every day. This will show if there are creatures in the plants which you just remove and dispose of.
Plants that do not say are shrimps safe are best avoided if you have shrimps or snails. But if you buy them, leave them for at least 2 weeks in a container with daily water changes to wash out any possible chemicals.