I have done the RF skin tightening and got burns on my face just like sun burn.

Redness is common following an infini treatment. Prolonged redness is not common, but may occur depending on the skin type and the infini settings. I would consult with your treating doctor if this has persisted for more than 2 weeks.

It is hard to say what your outcome will be. I would need to see you in person. There is no mention of what RF device was used. Redness after all RF is common, but should only persist for a few days, a week at most. Darker skin types need to be careful with prolonged redness because PIH can occur if it lasts for 2 weeks or longer. Steroids or vascular lasers should be used for prolonged redness. 

Uncommon with better devices, especially with Insulation. For non - insulated microneedling RF, if the intensity is very high and no insulation is used, then burns can occur- especially with shallow needle depths. You need to see a specialist for wound dressings, to reduce the chances of infection. All the best, Dr Davin Lim. Brisbane. Australia.