The Last Friend

You'll find this sidequest in "Eon - Eon Underground". You have to collect 3 items. After you accept a quest (look at the map for seeing a weird-looking icon as a level icon, to spot the side quest) you will see the quest icon by 3 missions. When you go to a mission with a sidequest you can press Y on a gamepad to get to that side quest. This means you have to beat a level with specifically selected dogs, those may not always be your favorite type, but it should be very doable, if not level up one of those dogs you use the most in that sidequest.

You can find this sidequest in "Monastery Hills - Wildlands". You have to collect 3 items. After you accept a quest (look at the map for seeing a weird-looking icon as a level icon, to spot the side quest) you will see the quest icon by 3 missions. When you go to a mission with a sidequest you can press Y on a gamepad to get to that side quest. This means you have to beat a level with specifically selected dogs, those may not always be your favorite type, but it should be very doable, if not level up one of those dogs you use the most in that sidequest.

You can find this sidequest in "Capitol D. City - Capitol D. City". You have to collect 3 items. After you accept a quest (look at the map for seeing a weird-looking icon as a level icon, to spot the side quest) you will see the quest icon by 3 missions. When you go to a mission with a sidequest you can press Y on a gamepad to get to that side quest. This means you have to beat a level with specifically selected dogs, those may not always be your favorite type, but it should be very doable, if not level up one of those dogs you use the most in that sidequest.

On the map you can find location icons with a purple circle and some pink and yellow. Complete all 4 for this achievement. You can find them on the following maps:
St. Petrol - Arid-Zone
St. Petrol - St. Petrol City
Eon - Eon Facility
Monastery Hills - Monastery Hills

You need to have Barbet 5 times alive at the end of a mission. I did this on the very first mission "Pitstop" after I got some upgrades so you can build more towers at the beginning of a level.

I did this achievement on the first mission "Pitstop", they don't have to be active after finishing the mission, you just have to place them.

You'll get this one easily later on in the game, but if you want to do it early, you can do it on the level "Firewall" in the first area, because you can play that level as long as you want and the game keeps giving you enemies, so you can get the scrap needed for those turrets easily on this mission.

You'll get this one later on easily as the level 3 version of this turret is awesome, but if you want to do it early on you can do it easily on the first mission "pitstop" after you get some upgrades to start with more scrap.

I think this was the easiest to do on the level "Firewall" in the first area because you can take as long as you want on that level as long as you don't kill the last firewall.

You unlock this instinct bar later on in the game and can activate it by pressing down the left and right thumbstick. I did this one the "firewall" mission in the first area just because you can take as long as you need on that mission.

This is easily done on the level "Firewall" in the first area. You need to upgrade the German Shephard to level 2 and then finish a mission with 10 times a level 2 wall up.

This is easily doable on any level, and you might have already done it before you know it was an achievement because you unlock both towers early on in the game and they are both amazing.

I did this on the first mission "pitstop" after you get some upgrades for starting a level with more scrap. Place a turret on every lane and adding more of them when you want to, but the enemies on this level are very easy. Just don't hit an enemy with your character.

This achievement is easily done on the mission "Family Feud" in the Capital D. City area. Run up to the "War Machine" and just starting hitting it, it won't attack you for a while and by that time you'll already have this achievement.

You can find this mission in the Capital D. City area. In each part of the level you have to stand in one of the spotlights to get detected. This achievement didn't unlock for me after I did it but later on it unlocked out of nowhere, but that might just have been a small bug.

Yolos are the guys which carry around a red jerry can. You can grab them with B and throw them on another enemy. Do this 30 times for this achievement. You can find those guys in the second area "St. Petrol - St. Petrol City"

In the EON Facility map, you can find the level "Modern Engineering", in this level you will see some kind of UFOs (1 during wave 2 and more during wave 3 and 4). You can kill those by doing an uppercut.