How to resurface my deck?

Stenciling your deck might be an option to consider. Heres a link with some ideas to look over. Pinterest and Houzz might have more visuals to help you decide if its an option you'd care to consider.

https://sweetparrishplace.com/wish-i-had-that-pretty-painted-deck/

There is a product called "Deck Over" designed to give new life to older wooden decks... check Home Depot or Lowe's... follow the preparation directions on the product.... and be sure and fix any structural issues so the deck stays sound

Hi Doris, You have a very nice patio. I would use a pressure washer to remove all the old paint chipping. If you come across a board with rough surface, just take the deck screws out and turn it over. Screw it back down. I'm sure painting the deck would brighten up your outdoor space. Best of luck to you.

Have you tried to pressure wash the unwanted paint off?

Preparation is a large part of a successful deck re-do. It will be important to remove all traces of the old finish before beginning to apply anything new.

Do NOT use Deck-over, or any similar product. They all fail. A google search will show this. Pressure wash, then sand, then wash again. Must be thoroughly dry. Buy a top quality deck stain, not stain for fences or walls.

Deck stains do not last. Even the best rarely last more than 5 years. Most should be re-stained every 3 years. Durability and longevity of products depend on sun exposure, climate and amount of use. You should err on the side of re-staining before wear becomes severe.

Transparent stains must be reapplied every year. Semi-transparent stains protect wood better, and are preferred by the pros for new decks. Semi-solid stains have more pigment so protect wood better but obscure the grain a bit. These are probably best for a very weathered deck. Cabot seems to have the largest color selection, but Olympic, Armstrong Clark, and Sherwin-Williams also make semi-solid stains. Solid color stains are too much like paint, but don't last as well as paint and are harder to remove. Only one brand of deck resurface coating—Gulf Synthetics Deck Revive—gets high marks; freezing weather undoes most of them. Oil-based stains are always better at penetrating wood, but will take longer to dry and cure. This link has articles that cover how to do everything. https://www.deckstainhelp.com/deck-stains/

To remove the rest of the old stain and coatings you should get a 5" random orbital sander with a hook and loop (velcro) pad. Make sure to get exact sandpaper discs for your model. Get a reliable brand such as Dewalt or Porter-Cable. The deck in your photo is too small for a large orbital sander, and a belt sander could gouge the surface. Start with 40 grit, then sand a second time with 80 grit to smooth. Be sure to clean your deck and let it dry before re-staining it. For long-lasting protection I would go with a semi-solid, oil-based stain.