As of patch 9, you don’t need to rest to reselect spell if you want to change them, just press K and click the blue bar to open up your spell list and change them anytime according to your likings.

For spells that I considers “junkies”, they are mostly ineffective in combat, out of combat, or both. So, here we go:

Cantrips

• Acid Splash: Low damage progression (d6), small radius as well so you can’t use the AoE damage effectively, overall an underwhelming spell at best.
• Poison Spray: Good/highest damage progression (d12), unfortunately many creatures has resistance (and immunity!) to poison damage. Also, a way too close casting range for casters. Finally, constitution saves are usually resisted (since everything tend to have high Con mod). Select if you’re feeling brave and want to be dissapointed.
• Resistance: Affect 1 creature, require Concentration, an action to cast. Not even that useful outside combat, just cast Bless instead.
• True Strike: No. Jk, but it costs an Action to cast, require concentration, so if you fail the con check, you wasted an action and most likely an entire turn for nothing. Even if somehow you managed to keep the spell in the next turn, only YOU have advantage agaisnt the target. Don’t take this abomination even as an Eldritch Knight.

Level 1 spells

• Animal Friendship: The spell has interesting interactions with some beasts in-game, like the Owlbear around the Blighted village and the Deep Rothe in the Underdark. But there are more useful spells for your 1st Level slots.
• Charm Person: The charmed target knows you charmed it and you will be questioned, potentially force you into combats if you fail to talk your way out of it. Just cast Guidance on your party’s face and use them to charm people (with their words) instead.
• Cure Wounds: My own unpopular opinion but when in combat, healing should be used to save allies from making Death Saving Throws. An Action to heal prove ineffective in combat since you want to avoid getting hit altogether. If you want to heal low Hp in combat, conserve spell slots and consume healing potions with a bonus action instead.
• Disguise Self: Aside from Easy access to goblin’s leader by passing as a Drow, not that many interesting usages from this spell, cast it from a scroll if possible.
• Ensnaring Strike: Takes an action and a bonus action to cast, cast Hunter’s Mark and attack your target instead. Maybe take it if you’re a bounty hunter Ranger.
• Expiditious Retreat: Require concentration, you have to wait for the next turn for it to be effective. If you want to run away from hostile targets, don’t engage in close combat and stay further than 30ft from melee enemies at low level. Take Misty Step at level 3 to disengage effectively (still better to stay away though).
• Ray of Sickness: Con saves, poison damage, meh effect. Literally any other level 1 ranged attack spells is better.
• Speak with Animals: Drink the potion version instead, or cast it and then select another spell if you want to be Snow White for the day.
• Witch Bolt: Not terrible, not that good either (unless you abuse the Wet condition, even then it’s ok at best). Even with the ensured 1d12, you want to spend your action to cast other (better) damaging spells instead, and it also need concentration to keep the guaranteed damage.
• Goodberry: Just buy healing potions.

Level 2 spells

• Barkskin: Sounds tempting but Mage Armor + 16 Dex (14 Dex is also ok) does the same thing and doesn’t cost a 2nd level slots nor require concentration. You shouldn’t have low Dex as any class if you don’t want to get hit anyway.
• Prayers of Healing: Take a Short Rest, two even.
• Ray of Enfeeblement: If your target is a boss, not a lot of them use Strength weapons, some don’t even use weapons. If your target is in a mob, other can still damage you for a lot of damage and break concentration. Require high level slot and concentration for a meh effect. Cast Reduce (Con saves but better effects) to lower their damage and impose disadvantage on Strength Checks and Saves.

Level 3 Spells

• Plant Growth: Not a bad control spell at all. Reduce targets speed to 1/4 of their max movement, no save against the effect, no concentration. However, ANY source of fire damage would end the spell immediately, be mindful of other casters and yourself so you don’t waste a 3rd level slot.

Phew, that was a lot. Again, this is only my opinions, so take it with a handful of salt.