Burner missions are higher-end PVE that require good skills (90 mil sp sounds perfect) and very specific ships/fits to run (all Burner missions limit the size ship you can use - mostly frigates/no battleships). While you can pick from dozens of ships to run almost any L4 security mission, Burner NPCs have few weaknesses to exploit and each must be fought with it’s precise weaknesses in mind. For example, there are 14 Burner missions total and I use 9 ships to run 12 of them. The 4 “Anomic Team” missions can generally be run with the same ship, but might require different damage types depending on which team you fight. Perfect fitting and ship skills for frigates and cruisers is VERY helpful. Implants will also make a big difference. Burner missions are given randomly from level 4 security agents and can be declined or quit without standing penalties.
Here are a couple guides you will find useful if you want to give them a try:
I would HIGHLY recommend that you use the Singularity test server to verify that your fits work prior to risking them on Tranquility. Also, you can use the “/booststandings” command on Singularity if you need to boost standings with an agent or corp - this will allow you to decline any missions you don’t want in order to get to the mission you need.
Welcome back and good luck.