Mfcttrf

I'm a beginner to the latex tikz and I want to draw this picture but dunno what's the best command or idea here

This is a special case of a cycloid curve, known as hypotrochoid.

documentclass[tikz,border=3.14mm]standalone
usetikzlibrarydecorations.markings
begindocument
begintikzpicture[insert arrow/.style=decoration=
 markings,
 mark=at position #1 with arrowstealth,postaction=decorate,
 bullet/.style=draw,fill=white,circle,thick,inner sep=2pt]
 draw[thick,insert arrow/.list=0.125,0.35,0.4,0.625,0.85,0.9] 
 plot[variable=t,domain=0:360,samples=101,smooth]
 (45+t-30*sin(4*t):2-0.8*cos(4*t));
 draw[very thick] (-3,0) -- (3,0);
 path (-2.8,0) node[bullet] (1.2,0) node[bullet];
endtikzpicture
enddocument

For your convenience I declared a style for that.

documentclass[tikz,border=3.14mm]standalone
usetikzlibrarydecorations.markings
begindocument
begintikzpicture[insert arrow/.style=decoration=
 markings,
 mark=at position #1 with arrowstealth,postaction=decorate,
 bullet/.style=draw,fill=white,circle,thick,inner sep=2pt,
 hypotrochoid/.style=/utils/exec=tikzsethypotrochoid/.cd,#1,
 insert path=
 plot[variable=t,domain=0:360,samples=101,smooth]
 (pgfkeysvalueof/tikz/hypotrochoid/rot+t
 -(360/(pgfkeysvalueof/tikz/hypotrochoid/n*pgfkeysvalueof/tikz/hypotrochoid/m))
 *sin(pgfkeysvalueof/tikz/hypotrochoid/n*t)
 :
 pgfkeysvalueof/tikz/hypotrochoid/outer radius
 -pgfkeysvalueof/tikz/hypotrochoid/inner radius*cos(pgfkeysvalueof/tikz/hypotrochoid/n*t)
 ), hypotrochoid/.cd,outer radius/.initial=2,
 inner radius/.initial=1,
 rot/.initial=45,n/.initial=4,m/.initial=1]
 draw[thick,insert arrow/.list=0.125,0.35,0.4,0.625,0.85,0.9,
 hypotrochoid=outer radius=2,inner radius=0.8,n=4,m=2.5];

 draw[very thick] (-3,0) -- (3,0);
 path (-2.8,0) node[bullet] (1.2,0) node[bullet];
endtikzpicture
enddocument

Then you can change e.g. n easily

draw[thick,hypotrochoid=outer radius=2,inner radius=0.8,n=6,m=2.5];

A solution with pstricks:

documentclassarticle
usepackagepst-plot,pst-node,multido

defx4*cos(t) + 2*cos(5*t)
defy4*sin(t)+2*sin(5*t)

begindocument

pssetunit=0.8cm
beginpspicture(-6.5,-6.5)(6.5,6.5)
psline[linewidth=1.2pt]-(-6.5,0)(6.5,0)
pssetplotpoints=500, plotstyle=curve, algebraic,linewidth=1.5pt
psparametricplot[linecolor=red, ArrowInside=->, ArrowInsideNo=4]06.28y
% define nodes on the curve
curvepnodes[plotpoints=4]04.712yP
curvepnodes[plotpoints=2]0.253.0yQ
curvepnodes[plotpoints=2]3.306.05yR
pssetdotstyle =triangle*, dotscale =1.4 , linecolor =red
multidoi=0 + 1,irot =0+ 904psdot[dotangle=irot,](Pi)
multidoi=0 + 1,irot =55+ 952psdot[dotangle=irot](Qi)
multidoi=0 + 1,irot =-25+ 952psdot[dotangle=irot](Ri)
psset dotscale =1.6, linecolor=black, dotstyle =Bo
psdots(P2)(2.5,0)
endpspicture

enddocument