Mosty u Jablunkova is off the beaten path village, do not expect anything opened in weekends and in the evening expect local restaurants, bars etc.
They close very early: at 7-8pm on business days and sometimes 10pm in weekends.
Once I was looking for grocery along main highway 11 (E-75) and all were closed on Sunday morning. Finally, I found one in nearby Jablunkov :-).
There was internet connection available in local library. But it's closed on both Saturday and Sunday. Ask locals for "Mistni knihova". It was opened 11.30 am - 7am Mon - Fri except on Wednesday: 11.30 am - 5 pm. I paid 15 Kc (Czech crowns) for each 15 minutes. Hmm... expensive as for "cheap" country.
Local, simple food was not spicy. There was nothing more than salt, black pepper, maggie and vinegar to improve (or to make worse) the taste of my dishes in Hotel Beskyd restaurant and in other places to eat around as well. If you used to add numerous spices or sauces to your dishes forget about it in local restaurants - it's off the beaten path Czech village.
No salsa, no other sauces, no tabasco, no chips, no nuts etc. Just soup + main course + drinks (beer!) + like above.
Czech beer in this area was always very cheap, much cheaper than in tourist restaurants in Prague and cheaper than in Poland as well - both in local pubs/bars and in stores. Add some inexpensive Czech spirits like Becherovka and cheap accommodations in this area. It makes the area popular among Polish, esp. young folks who used to drink a lot of beer and other alcohol there.
Whenever you drink even 1 small beer even don't touch your car. Remember: blood alcohol limit is 0 mg (zero!). Remember that it takes much time to lose alcohol drunk before: approx. only 0.02% per hour. So, when you drank a few beers better don't drive next day in the morning as well. I was told many times that Czech police was very hard about it - you maybe even arrested for DUI.