There is a pool enclosure industry and it may be near you. there are many different businesses that do pool repair if it's in your local pool store or the place you actually bought your pool from may help or pay for a new one
Depending on the type of enclosure you may need to purchase additional supplies. Could range anywhere from a cover to hardware. If repair needed is major you may want to contact a contractor.
You can not repair holes in sand filters made of any material. It would be safer for you to shut the system down at once. It would be best to replace that filter at your earliest convenience. You run...
GO TO YOUR NEAREST POOL STORE AND ASK THEM FOR A VINYL REPAIR KIT , THEY'RE PRETTY CHEAP.BRING A WATER SAMPLE WITH YOU MOST POOL STORES WILL TEST YOUR WATER FOR FREE.WHEN YOU GET HOME WITH THE KIT...