MTG Salvation

This is what I am currently running. Two FNM i have run this with have gotten 2-2, deck i really had a problem with was infinity deck. Also, would like suggestions to beat that?

https://www.mtggoldfish.com/deck/1411344#paper

This is what i am trying to get too

https://www.mtggoldfish.com/deck/1432469#paper

Just would like some feedback, i already know what i want to keep, just trying to tweak and mess around and test at the moment.

Really want to keep insult injury for creature attack, as well as double damage. So that i am gonna keep in this deck, as well as shrine of burning rage, was looking for feedback etc. just wanted suggestions for changes.

Do you mean Affinity in "Infinity" ?
If so your go-to SB cards for that should be: Shattering Spree, Abrade, Harsh Mentor and Smash to Smithereens.

By going Mono Red I'd suggest focusing on Wizards (4x Ghitu Lavarunner, 4x Soul-Scar Mage and 2x Grim Lavamancer/Viashino Pyromancer) to have Wizard's Lightning as your copies 5-8x of Lightning Bolt.

Young Pyromancer doesn't fit an aggressive deck like burn imho as it is very slow and doesn't represent an immediate threat.
You could probably use it in the SB if you wish to grind out attrition decks post-board.

Insult // Injury is a rather lackluster and very slow card for a burn deck (especially with only 18x lands so I'd advice against playing over any other 3-mana burn spell, be it: Exquisite Firecraft, Flame Javelin, Flames of the Blood Hand or even Stoke the Flames (can cost less with convoke).
Though I'd probably avoid 3-mana spells in the maindeck altogether.

Shrine of Burning Rage is a decent card but probably too slow so I'd use it a SB option to bring a gainst decks with lots of removal for your creatures as they'd unlike ly to bring in artifact removal and it could tick up and kill them slowly.

The Flame of Keld is another good option for "Mono Red Burn" especially with a really low curve to empty the hand quickly and gain card advantage of it.
It (and Bomat Courier) could also play well with Fiery Temper triggering "madness".

Rampaging Ferocidon could be a pretty good option here as well though probably in a more creature-lite version of the deck or as a SB option against lifegain.

thanks for some tips, i really look more at the artifact killing spells, also, starting to push over to r/w so included some other cards with white options, been mainly running into affanity and hexproof decks more than anything when i run my deck, what i have is what i feel good running, really wanted feedback on the second deck i listed for changes?

for your 2nd deck listed, i would remove the shrine and insult/injury from your deck. move your lightning helix and boros charm to main deck then; these are cards you want in your main deck if you are running white.

for the sideboard you need to increase the smash to smithereens count, and instead of fragmentize i would run wear/tear. you can also consider running path to exile.

kor firewalker is also a good sideboard choice. (replace reverberate)