RainThorn

Red line= red bar = weak signal (green, orange, red) no line = no bar = no signal

Same rocket with struts, Mainsail engine and Kickback SRB don't use launch clamps, be careful when attaching SRB to rocket, connect SRB somewhere above middle of SRB, 2:3 length ratio works fine, fine adjust if rocket is not stable. If you connect SRB too high or too low, rocket will start to vibrate, and if you try to fix that with clamps, it will vibrate even more. Use struts at bottom for clean separation start gravity turn early and change angle slowly and you will go into orbit with more than enough fuel in second stage and that stage will start to pick up speed when burns more than half of fuel Design is far from optimal and highly inefficient but it can go into orbit with more than enough fuel left.

Actually Flea has same thrust in career and in tutorial, what makes the difference is the thinner atmosphere in career.

Mainsail has silver nozzle, and his engine has black nozzle, it must be Skipper. But even with Mainsail TWR is too low. Rocket is unstable because it is hanging on launch clamp. Lower stages are pulling top stage down instead top stage pushing lower stages down. It will swing even with struts, just like pendulum.

Your have 140 T rocket and engine that can lift just 40 T. Your stack separators are for 1.2m tanks and you use 2.5 m tanks Launch clamp is at final stage and you need to release it as soon as you fire first engine. All that mass connected with weak decouplers and suspended on launch clamp will go up and down like yo-yo Use smaller tanks or stronger engines and correct size decouplers. also, you need to move reaction wheel up. If it is at first stage, it is useless, you have fins for that stage, and if it is at second stage it is right on top of your second engine adnd whole thing will blow up.

Click docking port on your ship and turn on control from here, then your directions will be correct, set docking port of other vehicle as target, align prograde/retrograde marker with target marker and then use SAS to align docking port axis with movement vector (align V marker with O and X markers). Turn SAS off just before contact.