amoeba

You don't need the crashmats though - we never had them in any of the clubs I've trained in and I've seen lots of people learn to roll, including some older and/or nor very sporty/confident ones and even some with physical disabilities. As long as you start low (from your knees or from a sitting position for backward rolls) and have a (competent) teacher watch you and correct you in the beginning, you should be completely fine. I've never seen any accidents from ukemi training (and that's including breakfalls).

For the forward roll I find it quite important to place your palm or the side of your hand on the floor, not the back. If you put the back, it'll be a lot less stable - leading to wrist and/or shoulder injuries should you crash on it.