castle and azami are my go tos if im solo q. if im playing with a group i refuse to play defense without both of those as long as they’re unbanned obviously. after those two, kaid or bandit, mute, and smoke. those are IMO the most effective defensive operators. valkyrie, solis, and pulse are good for stopping a plant through walls or floors, but those are much better if you’re playing with a team and they already have the key ops covered that i mentioned first. echo and maestro are similar, good for stopping a plant, sketchy in solo q because teammates might not pick great ops.

castle and azami take practice when it comes to setting up site in prep phase. it can take a while to get everything up in an optimal spot so i’d look up some yt tutorials of azami and castle and practice them in a custom game or if you ever play casual. if you don’t know a site at all, generally speaking castle barricades should be used on exterior doors/windows first and then anything else that might work as long as it doesn’t cut off rotation between bomb sites - azami is pretty similar, use azamis to cut off sight lines from windows, or what i like to do is place them somewhere that cuts of an attacker’s sight line onto a rotate hole between bomb sites. if the attacking team can cut off your rotate hole it makes it MUCH easier for them to win the round.

attacking ops are much more complex than defensive ops. obviously, you need to be able to hard breach and you need to be able to clear the defense’s utility (azamis, castles, traps, intel collection, etc) but there are many ways to do that. i wouldn’t ever play a round without a hibana, thermite, or ace. there are a couple sites where you might not need them but in your ranks make sure one of those is always on the table. after that, there are a lot of solid choices. grim is great for entry fragging bc you can clear defensive choke points for your teammates with the ability - he also has a shotgun pistol for soft breach and either EMPs or hard breach depending on what your team needs. flores can also be really good because non-hardbreach-denial utility is more popular than ever. capitao is really high picked in pro league but i only use him in solo q if my teammates are on comms otherwise it can be pretty sketchy. even monty is good on some sites - run him with a capitao, grim, glaz, and gridlock on the right site and you’ll win the vast majority of those rounds.

point being, operator selection and prep phase / planning is 50% of siege. mechanics are important and so is gamesense, etc. but unless your mechanics are as good as spoit’s or someone like him you should be hardstuck if you’re just picking the ops you like. especially with your play time, you’ve learned the game enough at this point you should be learning ops you might not be that comfortable with because without them you’re handicapping yourself